Mix Design

The Present paper investigates the influence of water absorption of ceramic waste aggregate on strength properties of ceramic aggregate concrete. Compressive strength and split tensile strength of concrete made with ceramic waste aggregate is studied with replacement of natural coarse aggregate by ceramic waste aggregate at 0%, 20%, 40%, 60%, 80% and 100%. Due to the influence of water absorption and external porcelain nature, strength of ceramic concrete is declining gradually but strength of ceramic concrete is more than the targeted mean strength even after replacing 100% of natural coarse aggregate.

State-of-the-Art Report on: Material Type, Requirements and Durability aspects of Sprayed Concrete in Tunnels The report summarizes a state-of-the-art for sprayed concrete applied for ground support in tunnel environments, in Sweden and several European countries, with focus on the components, the mix design and the guidelines and specifications. It focuses also on the addition of supplementary cementitious materials (SCM), where the use, the common practice and the long-term experience vary from country to country. The report presents numerous examples of applications in Sweden and seven other European countries. It also gives an overview about the possible exposure risks and summarizes the relevant durability issues. Along with specifications in international standards and guidelines it also reviews the national requirements in Sweden,

State-of-the-Art Report on: Material Type, Requirements and Durability aspects of Sprayed Concrete in Tunnels The report summarizes a state-of-the-art for sprayed concrete applied for ground support in tunnel environments, in Sweden and several European countries, with focus on the components, the mix design and the guidelines and specifications. It focuses also on the addition of supplementary cementitious materials (SCM), where the use, the common practice and the long-term experience vary from country to country. The report presents numerous examples of applications in Sweden and seven other European countries. It also gives an overview about the possible exposure risks and summarizes the relevant durability issues. Along with specifications in international standards and guidelines it also reviews the national requirements in Sweden,

Crack densities of Low-Cracking High-Performance Concrete (LC-HPC) bridge decks are compared to crack densities of control decks to investigate the benefits of the LC-HPC specifications developed at the University of Kansas. Specifications for construction of LC-HPC bridge decks are addressed. Bridge deck crack survey procedures are also summarized. Thirteen LC-HPC decks and thirteen control decks are compared by calculating crack densities and noting trends in cracking patterns over time. The results for eight additional decks are also presented. These include three LC-HPC decks, one control deck, and three decks which are considered neither LC-HPC nor control decks. The LC-HPC bridge decks have, with very few exceptions, lower crack densities than the control decks. Cracks are typically transverse above and parallel to the bars in the top layer of reinforcing steel, except at abutments, where cracks propagate longitudinally or perpendicular to the abutment.

self-compacting concrete is one of the most widely used concrete in the past two decades. The objective of present study is to introduce a new method for high strength self-compacting concrete mix design to both achieving maximum compressive strength and minimizing the cost of concrete. The proposed method is an analytical method. In this method, using optimization concepts such as Lagrangian function and Kuhn–Tucker conditions, and introducing a specific relationship to the compressive strength of concrete, without the need for computer computations, and based on a completely analytical method, provides optimal concrete mix design. The proposed method is a general approach and is applicable to all types of concrete. Here, for the purpose of introducing, the method used to high strength self-compacting concrete containing fly ash. An optimization model of the concrete mix design is first developed accounting for effects of experimental results. Then, using an optimization algorithm, optimal concrete mix design is obtained for the concrete with the strength under consideration. Results showed that the proposed method can provide optimal mix design of high-strength self-compacting concrete while water and cement amount are the minimum amounts required for self-compacting concrete.

Traditionally Stone Mastic Asphalt (SMA) is empirically designed, which could not guaranty an adequate stone-on-stone effect. To overcome this drawback, a research study was carried out having in view to develop a new SMA mix design approach for the optimisation of the stone-on-stone effect, based on new findings. To this end, the study included not only the evaluation of volumetric characteristics of SMA test specimens, but also the characteristics of coarse aggregates (CA) test specimens, prepared using different aggregate compaction methods: (i) bulk particles' specimens (compaction not applied), (ii) dry-rodded compaction, (iii) Proctor compaction and (iv) steel roller compaction. Bituminous mixtures' specimens were prepared by impact compaction using the Marshall compactor. In this context, the following test specimens' characteristics were assessed: air void content of compacted coarse aggregates (VCA), void in the coarse aggregate of compacted SMA (VCA MIX), air void content (porosity, Vv), voids filled with bituminous binder (VFB) and workability of nine different SMA. Results showed that pre-established grading envelopes did not allow the design or optimisation of the stone-on-stone effect. On the other hand, the new analytical mix design approach, complemented by the coarse aggregate Proctor compaction (55 blows per each layer, in a total of 5 equal layers), provides an alternative to current SMA mix design methods, since it: (i) is easy and cheap to perform, (ii) is time less consuming, and (iii) allows to obtain an air void and particle breakage more similar to the field.

Traditionally Stone Mastic Asphalt (SMA) is empirically designed, which could not guaranty an adequate stone-on-stone effect. To overcome this drawback, a research study was carried out having in view to develop a new SMA mix design approach for the optimisation of the stone-on-stone effect, based on new findings. To this end, the study included not only the evaluation of volumetric characteristics of SMA test specimens, but also the characteristics of coarse aggregates (CA) test specimens, prepared using different aggregate compaction methods: (i) bulk particles' specimens (compaction not applied), (ii) dry-rodded compaction, (iii) Proctor compaction and (iv) steel roller compaction. Bituminous mixtures' specimens were prepared by impact compaction using the Marshall compactor. In this context, the following test specimens' characteristics were assessed: air void content of compacted coarse aggregates (VCA), void in the coarse aggregate of compacted SMA (VCA MIX), air void content (porosity, Vv), voids filled with bituminous binder (VFB) and workability of nine different SMA. Results showed that pre-established grading envelopes did not allow the design or optimisation of the stone-on-stone effect. On the other hand, the new analytical mix design approach, complemented by the coarse aggregate Proctor compaction (55 blows per each layer, in a total of 5 equal layers), provides an alternative to current SMA mix design methods, since it: (i) is easy and cheap to perform, (ii) is time less consuming, and (iii) allows to obtain an air void and particle breakage more similar to the field.

Purpose This paper aims to review the effect of using recycled aggregates (RA) on the properties of recycled aggregate concrete (RAC) following the steady rise in global demand for concrete and the large generation of construction and demolition waste. Design/methodology/approach This study reviewed relevant literature of research work carried out by previous researchers, leading to a deeper understanding of the properties of both RA and RAC. The properties of RA and RAC reported in the various studies were then compared to their corresponding natural aggregate (NA) and natural aggregate concrete, as well as the specifications provided in different codes of practice. In addition, the mix design methods appropriate to RAC and the cost implication of using RA were reviewed. Findings Findings show that the contribution of RA to strength appears inferior in comparison to NA. The shortcoming is attributed to the mortar attached to the RA, which raises its water absorption capacity and lo...

The modern world is witnessing the development of extremely demanding structures right now. Concrete is an extremely important and widely used material. However, the reuse of construction waste is crucial when considering life cycle assessment (LCA) and the efficient recycling of construction materials. Given its potential to address sustainability and environmental challenges, using recycled materials in construction has attracted much attention. This study aims to examine what happens to concrete's compressive strength when recycled coarse aggregates (RCA) replace some of the conventional coarse aggregates. The aim is to study the impact of RCA content on the mechanical characteristics of concrete and determine its appropriateness for use in structural applications. The main objectives of this work is to determine and compare the Density, Workability, Compressive strength, split tensile strength, and Flexural strength of Recycled aggregate in relation to conventional aggregate also to ascertain the ideal percentage of aggregate replacement with recycled aggregate and to calculate the percentage change in strength for recycled aggregate at different levels of replacement. The research methodology involves carrying out laboratory experiments to examine the compressive strength, split tensile strength, and flexural strength of concrete specimens with different proportions of recycled concrete aggregate (RCA) substitutions. The typical coarse aggregates are substituted by recycled aggregates in various proportions (5%, 10%, 15%, 20%, 25%, and 30%) by weight in M25 grade concrete. The formulation of the concrete mix design is meticulously done to provide a consistent water-cement ratio and other crucial criteria. The study involves the process of casting and curing concrete specimens that contain varying amounts of recycled concrete aggregate (RCA). At certain curing ages (e.g., 7 days and 28 days), the specimens are tested for compressive strength, split tensile strength, and flexural strength in order to assess their mechanical capabilities. After that, the outcomes are contrasted with control samples made entirely of conventional coarse aggregates. Primary finding shows workability declines as the proportion of recycled trash rises, but it is kept stable with mixing.

The project report entitled "study the strength of M30 grade concrete using Glass fibre, synthetic and Natural fibre". The main objective of the study is to analyse the strength of M30 grade concrete using glass. Synthetic and natural fibre. In this process of identifying the strength of the used concrete we can conclude the best material to be mixed with for better long-lasting strength. These details of concrete and fibre are collected by a few articles and through some experiments Glass, jute, nylon fibres are taken in the ratio of 0.5% ,1.5% ,2.5 %. Complast sp420 is used for water reducing. Mixing of fibres in concrete helps in increasing 50% of strength then conventional concrete with better increase of mechanical properties. We are casting cubes for compression and cylinders for tensile strength. Chairs and tables are used for better understanding. This study focuses on evaluating the strength characteristics of M30 grade concrete incorporating three distinct types of fibres: glass, synthetic, and natural. The investigation includes a comprehensive analysis of the mechanical properties of these fibrereinforced concrete mixes. Various tests such as compressive strength, and split tensile strength are conducted to assess the performance and effectiveness of each type of fibre. The research methodology involves the preparation of M30 grade concrete specimens with varying fibre content for each type. The concrete mixes are cured and subjected to a series of standard tests to evaluate their strength and durability. The study aims to understand the influence of glass, synthetic, and natural fibres on the overall performance of M30 grade concrete and to identify the optimal fibre dosage for enhanced structural properties. Results obtained from the experimental tests are analysed and compared to ascertain the impact of each fibre type on the concrete's strength characteristics. The findings aim to contribute valuable insights to the field of concrete technology, providing a basis for informed decision-making in the selection and application of fibres to improve the performance of M30 grade concrete in structural applications. Through experiments with considerable apparatus, process and ratios we can conclude the

The granular sub-ballast layer commonly used in the construction of modern railway tracks, but its use involves a significant consumption of natural aggregates, which, moreover, must meet certain requirements that are sometimes unavailable. Therefore, the possibility of using recycled aggregates arises to promote sustainable development. In this context, this research focuses on assessing the feasibility of using RAP (Reclaimed Asphalt Pavement) as a sub-ballast layer in railway tracks, these recycled materials can contribute to increased load-bearing capacity and waterproofing of the lower layers due to the presence of adhered bitumen, studying the optimal application process to achieve a layer with high mechanical performance. It presents a laboratory investigation on the influence of different design factors on the mechanical performance of the layer, evaluating the effects of RAP characteristics, and the impact of the compaction procedure. Although these recycled materials primarily presented challenges in terms of size, particle distribution, and strength, which differ from the aggregates commonly used in similar high-demand layers, laboratory tests simulating expected service conditions for these materials in railway tracks have shown the viability and suitability of using recycled asphalt materials to achieve more sustainable railway tracks. Under compaction conditions at temperatures commonly achieved in construction (above 40 ºC) and considering its particle size distribution, it is possible to create a layer with high performance in terms of strength and durability.

Fibre Reinforced Self Compacting Concrete(FRSCC) is emerging as improved structural material with enhanced mechanical properties of higher Young’s modulus, increased compressive strength, crack resistance and durability. The present studies are aimed at understanding the effect of mechanical strength properties of FRSCC using glass fibres. In this study anti-crack high dispersion glass fibres with aspect ratio of 857 are used in M30 grade Self Compacting Concrete (SCC) with a dosage of 0.60kg/m3. The stress-strain behaviour of Glass Fibre Reinforced Self Compacting Concrete (GFRSCC) was investigated on standard cylinders of 150mm x 300 mm and mathematical models in the form of polynomial equations were developed. Subsequently, wall panels of 1500mm x 1000 mm size with 75mm thick(t) were cast with the same mix as investigated for mechanical properties. The wall panels were tested under vertical compressive load with minimum eccentricity with top and bottom edges fixed until failure. ...

9 This study aims to achieve a further improvement in the mix design of crumb rubber 10 modified (CRM) mixtures maximizing the use of End-of-life tires. The paper contributes to the 11 deeper understanding of the mechanisms characterizing the mix design process of rubberized 12 asphalt (dry process). In particular, it has been verified that an analytical approach can be applied 13 to determining the recovered deformation of the crumb rubber in the post-compaction phase. 14 Knowing the deformation recovered by the rubber allows adjusting the compaction process by 15 using a correction factor in order to finally meet the requirements of voids content for the asphalt 16 mixture considered. It has been seen that the correction factor depends on the crumb rubber 17 quantity and size, the bitumen content and the type of asphalt mixture. Moreover, once the target 18 voids have been established, a mathematical formula can be applied to determining the 19 maximum allowable amount of rubber t...

Amorphous silica and alumina of metakaolin are used to adjust the bulk composition of black (BSS) and white (WSS) steel slag to prepare alkali-activated (AAS) mortars consolidated at room temperature. The mix-design also includes also the addition of semi-crystalline matrix of river sand to the metakaolin/steel powders. The results showed that high strength of the steel slag/metakaolin mortars can be achieved with the geopolymerization process which was particularly affected by the metallic iron present into the steel slag. The corrosion of the Fe particles was found to be responsible for porosity in the range between 0.1 and 10 µm. This class of porosity dominated (~31 vol %) the pore network of B compared to W samples (~16 vol %). However, W series remained with the higher cumulative pore volume (0.18 mL/g) compared to B series, with 0.12 mL/g. The maximum flexural strength was 6.89 and 8.51 MPa for the W and B series, respectively. The fracture surface ESEM observations of AAS showed large grains covered with the matrix assuming the good adhesion bonds between the gel-like geopolymer structure mixed with alkali activated steel slag and the residual unreacted portion. The correlation between the metallic iron/Fe oxides content, the pore network development, the strength and microstructure suggested the steel slag's significant action into the strengthening mechanism of consolidated products. These products also showed an interesting adsorption/desorption behavior that suggested their use as coating material to maintain the stability of the indoor relative humidity.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

The main objective of this work is to identify, based on experimental physical characteristics investigation, the grout types with potential capacity of residual radionuclides stabilization into storage container of low level radioactivity waste (LLW). The grouts matrix based on Portland cement or special cement with lead slag addition and various fillers (limestone, L or pulverized fly ash, PFA) were carried out with river fine sand or lead slag recycled fine sand. The Portland cement /PFA or L ratios have had values of 30/70; 50/50 and 70/30, and cement/sand ratio was of 1/1. There were tested on the physical characteristics – fluidity which assesses the filling ability of the LLW storage container, the density which reflects radionuclide shielding capacity, the shrinkage correlated with the microcracking potential and mechanical strengths evolution required of the long time secure LLW management. Obiectivul principal al acestei lucrări este de a identifica, pe baza datelor experi...

The aim of this study is to investigate the effect of different parameter of mix composition on fresh and rheological properties of printable mortar. Different binders were tested such as limestone filler (LS), and fly ash (FA). The water/binder ratio of 0.50 was used in this investigation. Superplasticiser (SP), viscosity modifying admixture (VMA) and sisal natural fibres (NF) were used in the investigation at different percentage. Furthermore, positive effect of fibres can be reversed when the dosage in fibres is too high (difficulties to extrude and drainage phenomenon which led to a stiffening of the mix). VMA caused an important loss of workability and time gap which influenced the passing ability of the mix through the extruder. Adding sisal fibres led to a greater yield stress, higher cohesiveness of the mix. Increase SP led to an increase in slump flow and penetration values and reduced the yield stress which can affect the stability of the shape of printed layers.

This paper presents the study carried out using the extended Equivalent Mortar Volume (EMV) mix design technique, for concrete made of recycled aggregates (RA) and steel fibre (SF). The expansion of the EMV approach is necessary to encourage the use of fine recycled aggregates (FRA) in concrete manufacture. To this end, the same replacement ratio obtained for coarse recycled aggregates (CRA) using the EMV principles, was applied to the FRA for concrete production. Furthermore, SF was added to improve the mechanical behaviour of RA-concrete developed with this method. Altogether, four mixes were developed using a constant waterto-cement ratio of 0.42 thus: reference mix labelled conventional concrete (CC) prepared with natural aggregates (NA); crushed aggregate concrete (CAC) mix designed with the conventional method and made of 100% RA; blended aggregate concrete (BAC) mix prepared with the EMV guide and composed of both NA and RA; and steel fibre-reinforced blended aggregate concrete (SFRBAC) mix prepared by adding optimum SF to the BAC mix. Then, cubical, cylindrical and prismatic specimens were produced from the mixes to investigate different properties of concrete. The experimental results show that the mechanical properties of concrete are not adversely affected by the presence of FRA. Also, the EMV mix design provision offers a better result than its companion conventional approach, even with about 30% reduction in cement content. The addition of SF mainly controlled crack development and induced a ductile failure mode.

This study proposes test methods for assessing the printability of concrete materials for Additive Manufacturing. The printability of concrete is divided into three main aspects: flowability, setting time, and buildability. These properties are considered to monitor the critical quality of 3DCP and to ensure a successful print. Flowability is evaluated through a rheometer test, where the evolution of shear yield strength is monitored at a constant rate (rpm), similar to the printer setup. Flowability limits were set based on the user-defined maximum thickness of a printed layer and the onset of gaps/cracks during printing. Setting time is evaluated through an ultrasonic wave pulse velocity test (UPV), where the first inflection point of the evolution of the UPV graph corresponds to the setting time of the concrete specimen. The results from this continuous non-destructive test were found to correlate with the results from the discrete destructive ASTM C-191 test for measuring settin...

On the basis of the principle that a concrete is composed of a liquid phase (paste) and a solid phase (aggregates with fixed gravel/sand ratio), the concrete self-compacting properties come necessarily from those of the paste. The present work is the continuity of a first phase of the testing already conducted, which resulted in obtaining an optimal self-compacting cement paste composition. This paste will be used to prepare a self-compacting concrete (SCC), while passing from the scale of the cement paste to that of the concrete, by injecting wet aggregate to the self-compacting paste. The excess paste theory was used to determine the thickness of the paste coating each aggregate with a given diameter of constituting granular skeleton, then generalized for the determination of the quantity of total paste allowing the flow of the concrete by decreasing frictions between the grains of its granular skeleton. This approach was also experimentally validated. The influence of the granula...

This work consists in studying the effect of the water saturation of aggregates on the development of shrinkage and the potential risk of cracking of concrete. Different concretes were obtained from a given concrete mixture by changing only the degree of saturation of porous gravels. Three degrees of saturation were studied, namely: 0% (dry aggregates), 50% (partially saturated aggregates) and 100% (saturated aggregates). From the experimental results, the early age behaviour and the mechanical properties of the concrete strongly depend on the degree of water saturation of aggregates. As a consequence, the potential risk of cracking of these different concretes should be different. These results highlight the fact that the concept of the effective water remains theoretical; because it does not take account the kinetics of water absorption of aggregates and the hydration of the cement.

Mechanical properties, such as compreessive, flexural and tensile splitting strength, considering an additional 10% volume of SF Geo-polymer concrete, as recommended by international codes, to partially replace slag cement to partially to medium strength, Geo-polymer concrete has not been investigated. till now. The present study investigates the mechanical properties of medium strength SF geo-polymer concrete made according to this construction practice by partial replacement of slag cement. The effect of SF on the strength of compreessive, flexural and tensile splitting of rigid Geo-polymer concrete is investigated. Seven geo-polymer concrete mixes are prepared by replacing Portland slag cement (PSC) partially with SF from 0 to 30%. The Indian standard recommends reducing the target strength of conventional Geo-polymer concrete in terms of water-to-cement ratio (w / c). In the present study, to propose the relation of compreessive strength with watercement ratio, the behavior of RCA Geo-polymer concrete prepared from two samples of parent geo-polymer concrete with different age groups is investigated. The effect of age and number of recycling on properties such as capillary water absorption, drying shrinkage stress, air content, flexural strength and tensile splitting strength of RCA Geo-polymer concrete are investigated. And the compreessive strength gradually decreases with the number of recycling.

The organic content contained in the sand can affect the quality and improvement of the concrete which will slow down the concrete process. Sand originating from the Batanghari watershed is pretty much inspected in the laboratory of the Faculty of Engineering. The design of the concrete shows that the organic content of sand originating from the Batanghari river basin is quite high. There are 2 variations of the concrete test object, unwashed sand and washed sand, The source of sand from the Batanghaari river Sembubuk village, Kec. Jambi Outer City District. Muaro Jambi which refers to the British standard and ASTM C-33. The aim is to get the levels of organic impurities contained in the coarse sand of the Batanghari river and to determine the effect of medium sand on the compressive strength of concrete. The implementation method refers to SNI 7656:2012 regarding the test method for the procedure for selecting mixtures for normal concrete, heavy concrete, and mass concrete. The con...

One of the main advantages of warm mix asphalt (WMA) used as an alternative to conventional hot mix asphalt (HMA), is to reduce mixing and compaction temperatures. This laboratory study was conducted with the aim of determining physical properties of WMA mixes produced using foam bitumen technology (WMA-Foam), while applying different mixing and compaction temperatures. The effect of laboratory compaction method on mix properties was also investigated. WMA-Foam mixes were produced, adding a soft bitumen to coarse aggregate particles at the first stage, then a hard bitumen, transformed into foam bitumen using a laboratory foam making device, was directly added to aggregates at the next stage. Compaction was performed separately applying both Marshall and gyratory compactors (GC) at different temperatures. Marshall Stability and void contents of the samples were determined as two major parameters for characterizing WMA-Foam mixes. Moisture susceptibility and rutting potential of WMA-Foam samples were evaluated using indirect tensile strength (ITS) and wheel tracking tests. In addition, separate samples were prepared, in which hydrated lime powder was added as an anti-stripping agent to improve adhesion properties of the mixes. Comparing the results of WMA-Foam mixes with control HMA of the same content, resulted in mixes with similar properties of the control HMA, with appreciably lower production and compaction temperatures of the former. It was also resulted that mixes compacted with gyratory compactor were less sensitive to temperature variations than those compacted with Marshall Hammer.

One of the main advantages of warm mix asphalt (WMA) used as an alternative to conventional hot mix asphalt (HMA), is to reduce mixing and compaction temperatures. This laboratory study was conducted with the aim of determining physical properties of WMA mixes produced using foam bitumen technology (WMA–Foam), while applying different mixing and compaction temperatures. The effect of laboratory compaction method on mix properties was also investigated. WMA–Foam mixes were produced, adding a soft bitumen to coarse aggregate particles at the first stage, then a hard bitumen, transformed into foam bitumen using a laboratory foam making device, was directly added to aggregates at the next stage. Compaction was performed separately applying both Marshall and gyratory compactors (GC) at different temperatures. Marshall Stability and void contents of the samples were determined as two major parameters for characterizing WMA–Foam mixes. Moisture susceptibility and rutting potential of WMA–F...

The Bailey Method provides a set of tools for the design and the evaluation of aggregate packing and voids of asphalt concrete grading while maintaining appropriate mixture workability and durability. In this study, concepts, procedures and parameters of the Bailey Method, that is strongly based on sieves and aggregate sizes adopted in the USA, were applied in the European perspective. To this aim, two sets of asphalt mixtures were designed applying the Bailey Method. The study shows that the European practice for aggregate grading design allows the application of the Bailey Method criteria confirming the validity of its basic principles.

This study consists in experimentally determining a formula of mortar got from silty sands of Togo for the purpose of optimal mechanical properties. 1,443 4cmx4cmx16cm test tubes of mortars made from silty sands of 12 sites of extraction of Togo are prepared at variations of water and cement. The results show that for the water-cement ratio (E/C) of 0.5, the evolution of resistances in compression at 28 days of age (σc) increases exponentially to C/S and E/S ratios ranging between 0.311 to 0.512 and 0.156 to 0.256 (σc=aeb1(C/S)=aeb2(E/S) with 0.061c≈19MPa to 35,45MPa). Two formulas of rich mortars (E/C=0.5, C/S>0.512 and E/S>0.226) and lean (E/C=0.5, C/S<0.311 and E/S<0.156) silty sands taken in Togo are therefore defined.

DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:

Recycled coarse aggregate (RCA) is produced by crushing the demolition waste from concrete structures. The construction and demolition waste is primarily used for landfill sites which are causing significant damage to the environment and developing serious problems. The use of the RCAs created from the processing of construction and demolition waste in new construction has become more important over the last two decades as it conserves the non-renewable natural resource of virgin aggregates. With a view to the above needs, the present study is aimed to determine the strength properties of RCA concrete depending on the various content of RCA and to compare them to the strength properties of concrete made with natural coarse aggregates (NCA). The fine aggregates of high FM of 3.0 were used for recycled and natural concrete. After performing the compressive strength test, it was found that concrete made with fully replaced RCA has less strength than concrete made with NCA but not much. So, RCA can be used as a replacement for NCA in concrete production. In addition, full replacement of RCA can be used in structures of less importance such as temporary walls, the base of roads, light traffic roads, pavements in college campuses etc.

Additive Manufacturing (AM) in the construction industry is still in a relative state of infancy. Research has focused on heavy, ground based methods, with the building envelope determined by the dimensions of the deposition system. By comparison, the approach of using robots is not geometrically restricted but requires a degree of miniaturisation to the deposition process. Many studies utilise the AM principal of Fused Deposition Modelling (FDM), which creates an object by extruding a suitably viscous material through a nozzle and depositing one layer at a time. Crucial to the development of cementitious materials for Additive Building Manufacturing (ABM) without formwork, is the material possessing both workability and buildability, and appropriately balancing the contrasting requirements of these properties. Cementitious materials are typically brittle, requiring reinforcement to provide tensile and flexural capabilities. Reinforcing steel bars are not naturally compatible with ABM and chopped fibres are considered as a viable alternative. This paper investigates the development of a fibrous cementitious mortar suitable for use with a miniaturised deposition system based upon the FDM principal. Three types of fibres-Polypropylene, alkali-resistant glass and Polyvinyl Alcohol (PVA)-were investigated to assess workability, buildability, suitability for a miniaturised ABM deposition method and contributions to the mechanical strength of a mortar. PVA fibres provided the best buildability and increased flexural strength, with the appropriate quantity contained in mixes being informed by the negative impact upon workability.

The fused deposition principal of additive manufacturing (AM) involves the deposition of a material one layer at a time allowing the creation of an object from 3D digital design. The associated reduction in the amount of material wastage offers benefits to the construction industry and over the last decade, investigations have been carried out using cementitious materials for AM in construction. Central to the profile of the technology increasing in the industry is the development of a suitable cementitious material which may be deposited without formwork. Research currently consists of ground based gantry or robotic arm methods reliant upon suitable terrain and environmental conditions. This paper presents development of fibrous cementitious mortars and pastes suitable for a miniaturised deposition system designed for use in a multiple agent AM approach. Synthetic PVA, aramid and kevlar fibres along with natural fibres from the banana plant were investigated to evaluate contributions to the workability, buildability, mechanical strength and mechanism of failure of cementitious composite material. The addition of fibres to a cementitious matrix augmented by synthetic hydrocolloids results in compressive and flexural strength increases and transforms the method of failure from brittle to ductile. Results suggest PVA and kevlar fibres are suitable for a composite cementitious material with optimised rheology specifically designed for a multiple-agent, miniaturised deposition approach for AM.

In this study, the effect of incorporation of recycled glass fibre reinforced plastics (GFRP) waste materials, obtained by means of shredding and milling processes, on mechanical behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates, between 4% up to 12% in weight, were incorporated into polyester PM materials as sand aggregates and filler replacements. The effect of the addition of a silane coupling agent to resin binder was also evaluated. Applied waste material was proceeding from the shredding of the leftovers resultant from the cutting and assembly processes of GFRP pultrusion profiles. Currently, these leftovers as well as non-conform products and scrap resulting from pultrusion manufacturing process are landfilled, with additional costs to producers and suppliers. Hence, besides the evident environmental benefits, a viable and feasible solution for these wastes would also conduct to significant economic advantages. Design of experiments and data treatment were accomplish by means of full factorial design approach and analysis of variance ANOVA. Experimental results were promising toward the recyclability of GFRP waste materials as partial replacement of aggregates and reinforcement for PM materials, with significant improvements on mechanical properties of resultant mortars with regards to waste-free formulations.

Various studies in the field of concrete were carried out in an effort to improve the quality of concrete, thetechnology of the research and experiment materials intended to answer the increasingly high demands on the useof concrete.One way to reduce excessive mining of natural materials is by utilizing waste glass bottles and brown sugar,especially glass bottles which area lot of waste and accumulate in the environment around the house.This study aims to analyze the compressive strength of concrete using wasteglass bottles and brown sugar as a substitute for fine aggregate and water. Mix Design in glass bottles and brownsugar as a substitute for fine aggregate and water. Mix Design in This study uses the SNI 2000 method. Thecomposition of glass bottle waste is 5% and 10% to fine aggregate while brown sugar is 0.25% and 0.50% againstwater. The specimens were cylindrical in shape with a diameter of 15 cm and a height of 30 cm as many as 24specimens aged 7, 14 and 28 days. The results...

Dalam penelitian ini akan mencoba menganalisis kandungan lumpur dan kandungan organis dari pasir quarry jepara yakni Kali Tempur, kali Batealit dan Kali Tengguli, tujuan dari penelitian ini adalah mengetahui hubungan antara kandungan lumpur dan kandungan organis dari masing-masing pasir tersebut sehingga dapat digunakan sebagai bahan konstruksi. Metode yang digunakan adalah dengan melakukan pengujian dengan sistem kocokan dan sistem cucian yakni pada pecucian 0, 30, 60 dan 90 kali pencucian. Adapun hasilnya adalah Kandungan lumpur dari tanpa cucian sampai 90x cucuain diperoleh bahwa berturut-turut pasir kali Tempur 15,38%, 9,75%, 7,3% dan 3,03 %. Pasir kali Batealit sebesar 23,98%, 13%, 3,19% dan 0,8 %. Pasir kali Tengguli sebesar 5,90%, 13%, 4,58 dan 3,05%. Dari hasil tersebut menunjukkan bahwa pada pencucian 0 x dan 30 x semua pasir belum memenuhi standar PBI 1971 < 5%, pada pencucian 60 x hanya pasir kali Batealit dan pasir Kali Tengguli yang sudah memenuhi serta pada cucian 9...

3D printing (3DP), commonly known as additive manufacturing (AM), is a promising technology that can fabricate three dimensional complex shape prototypes directly from computer-aided design (CAD) model without any tooling and human intervention. Owing to its peculiar characteristics, AM is widely used in many industries to assist in the design, manufacture and commercialization of a product. More recently, this technology has been extended to building and construction (B&C) application in order to mitigate some of the critical issues such as shortage of skilled labour, high production cost and construction time, health and safety concerns of the workers in the hazardous environment etc. However for successful implementation, proper selection of materials and their mix design is highly recommended, which is a challenging task. This paper summarizes the current available 3DP systems from literature and the respective materials that have been used thus far by various experts, industrie...

The inclusion of fly ash class C, which is widely available locally, can influence the progress of strength and durability qualities of geopolymer concrete when exposed to significant environmental conditions. Alternative geopolymer combinations appropriate for curing at ambient temperatures were employed to investigate the impacts of high calcium (class C) fly ash-based geopolymer concrete. A combination of sodium hydroxide and sodium silicate alkaline activator was used to react with fly ash class C. Fly ash class C was added as 20% of the total binder without using ordinary Portland cement. The durability of fly ash class C-based geopolymer concrete in sulphate environments was tested. The changes in weight, length, and compressive strength due to exposure in magnesium sulphate solution for different periods of time were determined. The test results demonstrate that fly ash class C-based geopolymer concrete cured at normal temperatures has good resistance to sulphate attack. In general, inclusion of high calcium fly ash in geopolymer concrete improved strength and performed satisfactorily in sulphate environments when cured in ambient temperature.

This recommendation describes how to evaluate the presence of potentially active bitumen in recycled asphalt (RA) materials through the cohesion test. The experimental protocol is designed according to the research performed by the RILEM Technical Committee 237-SIB ''Testing and characterization of sustainable innovative bituminous materials and systems'' with the purpose, to develop a new, simple and fast method for the characterization of RA while limiting the need for conventional rheological tests. The guidelines in this recommendation focus on the testing procedure including specimen preparation, data analysis and provide information on the preparation of a tests report.

Internal curing of high-strength concrete has been the subject of extensive research for the last decade. The concept of protected paste volume has been one of the most significant theoretical approaches to internal curing. In this paper, the applicability of the protected paste volume concept to internal curing is re-evaluated in view of recent experimental evidence. It is shown, that the concept of protected paste volume and recommendation to limit the spacing factor to approximately 200 μm, cannot be extended to internal curing of high-strength concrete, since the distance of penetration of the internal curing water into the surrounding matrix depends mainly on the availability of internal curing water to the surrounding cementitious matrix. The pore structure of LWA and the size of SAP particles seem to have a marked influence on the availability of internal curing water and thus are factors of greater importance than the spacing factor.

The alteration in quantities for preparing sundry concrete mix has been a great challenge for the concrete industry. The present work investigates replacement of sand and cement with glass powder (GP) and fly ash (FA) respectively. GP being rich in silica has the potential to replace sand as fine aggregate in concrete. The propensity of using FA as a supplementary cementitious material was done to improve the properties of concrete that utilized finely crushed waste GP, especially with regards to inhibit the alkalisilica reaction (ASR). This proportionate replacement of sand with GP can possibly solve the ongoing crisis of sand procurement through mining which is a direct cause of erosion. The term environmental economics has been used to analyse the burgeoning effects on nature and to alleviate the increasing cost of construction. The GP was used in proportions of 0%, 5%, 10%, 15% and 20% as a fine aggregate replacement. An experimental study was made where compression strength, flexural strength, tensile strength and modulus of elasticity of proportioned concrete mixes were examined and compared. Therefore viable improvisation can be done by using FA and GP as binders to make an efficacious concrete.

The compaction temperature of crumb rubber modifier (CRM) asphalt mixes needs to be determined cautiously because the viscosity and the amount of the CRM binder affects the compactability of the mixtures. In this study, a laboratory investigation was carried out on the volumetric properties of CRM mixtures fabricated using the Superpave gyratory compactor (SGC) and the Marshall compactor as a function of compaction temperature. Two CRM binders were incorporated into HMA mixtures. Two other mixtures were produced with the control binder (PG 64-22) and SBS-modified binder (PG 76-22) and used for comparison purposes. The CRM binders were produced using one base binder (PG 64-22) with 10% or 15% ambient CRM (À40 mesh) by weight of the binder. For this research, the Superpave and the Marshall mix designs for four different asphalt binders were conducted to determine the optimum asphalt contents (OAC). A total of 128 specimens were manufactured using the SGC and the Marshall compactor at various compaction temperatures (116, 135, 154, and 173°C). The volumetric properties were obtained and analyzed using the statistical methods. The results from this study indicated that (1) the compaction temperatures used in this study significantly affected the volumetric properties of the CRM mixtures, regardless of the compaction methods (the SGC and the Marshall compactor); (2) the CRM mixtures in both the SGC and the Marshall compactor showed the higher VMA values than the control and SBS-modified mixtures; (3) a general trend of the volumetric properties as a function of compaction temperature and compaction method was found for the CRM mixtures used in this study.

Concrete, a composite material made with cement, aggregates, admixtures or super plasticizers and water comprises in quantity the largest of all man-made materials. Although aggregates make up three fourths of the volume of concrete, the active constituent of concrete is cement paste. The properties and performance of concrete are largely determined by the properties of the cement paste. Super plasticizers in concrete confer some beneficial effects such as acceleration, retardation, air entrainment, water reduction, plasticity etc., and these effects are due to their action on cement. The scientists are mainly concentrating to develop the specialized concretes, to enhance the service life of the buildings, and to provide satisfactory performance under aggressive environments. In the present experimental investigation M 30 concrete is used as control mixture with four different super plasticizers namely SNP (Sulphonated Naphthalene Polymer) 1, SNP 2, SNP 3 and SNP 4. Strength of modified concrete is compared with the normal concrete i.e. without super plasticizer. The results show that the significant improvement in the strength and workability of modified concrete.

The workability-dispersion-cohesion method is a new proposed method for the design of normal concrete mixes. The method uses special coefficients called workability-dispersion and workability-cohesion factors. These coefficients relate workability to mobility and stability of the concrete mix. The coefficients are obtained from special charts depending on mix requirements and aggregate properties. The method is practical because it covers various types of aggregates that may not be within standard specifications, different water to cement ratios, and various degrees of workability. Simple linear relationships were developed for variables encountered in the mix design and were presented in graphical forms. The method can be used in countries where the grading or fineness of the available materials is different from the common international specifications (such as ASTM or BS). Results were compared to the ACI and British methods of mix design. The method can be extended to cover all types of concrete.

Measuring the rate of water absorption of the aggregates used in mortars and concrete mixtures is critical for the production and application of the final product. This is because it determines the amount of water required to achieve proper cement hydration and thus ensure the appropriate consistency. This paper focuses on the study of a new technique for measuring retained water in fine aggregates as an alternative to other conventional techniques specified in several international standards. In order to obtain results, the procedure described in the existing standards takes more than 24 hours. Additionally, it involves high consumption of heat energy due to the use of drying ovens. Furthermore, the results obtained remain highly variable and therefore discussed by the scientific community. In this research, a novel technique based on a halogen moisture analyzer was implemented. The technique was assessed using an experiment design with a surface response model. The most important factors and levels were identified together with the interactions between them. Finally, the model was validated and the results obtained with the proposed technique were compared with those obtained via conventional techniques in order to verify that they were equivalent.