Mix Design

Design of concrete mixtures is the process of selecting the most economical and practical proportions of all the ingredients to produce quality concrete. Because of the nature of the mix design process and all the heuristic knowledge that is associated with it, concrete mix design lends itself well to a knowledge-based application. This paper describes a prototype knowledge-based system called HPCMIX that can be used to load the experimental data, develop several statistical models to determine the responses, evaluate the predicted models, and predict the 28 days strength and slump. It can also be used to design HPC mix proportions that are subjected to specified constraints (e.g. strength and slump). It is capable of selecting proportions of mixing water, cement, supplementary cementitious materials, aggregates and superplasticizer, with consideration being given to the effects of air content as well as water contributed by superplasticizer and moisture conditions of aggregates. As most of knowledge-based systems, this system has explanation facilities, can be incrementally expanded, and has an easy to understand knowledge base. The system was tested on a sample project. The system's selection of the concrete proportions compared favourably with the expert's selection. The system is very useful for civil engineering students as well as practicing engineers.

The development of biodegradable polymer composites is a promising alternative for obtaining environmentally friendly materials. The aim of this study was to develop polyhidroxybutyrate (PHB) composites with rice husk ashes and evaluate mechanical properties by tensile tests, determining stress and elongation at break and modulus of elasticity, flexural strength test and Izod impact tests, as well as density and hardness. The composites showed impact strength up to 25% greater than the polymeric material containing only PHB. Also for the testing of tensile strength in bending showed significant improvements in the composites up to 15%. The results indicate that the ash as filler in PHB is viable for applications in materials that already use the PHB in pure form, considering the technical aspects studied (processing and properties) and the environment, since in most tests there was a gain or maintenance of properties when compared to PHB.

Concrete is no longer made of aggregates, Portland cement and water only it is not always incorporate so it requires at least one of the additional ingredients such as admixtures, supplementary Cementitious material or fibers to increase the strength and durability. Rice husk ash is one of the pozzolanic materials that can be blended with Portland cement for the production of durable concrete. Supplementary Cementitious materials prove to be effective to meet most of the requirements of durable concrete. Rice husk ash is found to be greater to other supplementary materials like silica fume and fly ash. In the current study an attempt has been made to investigate the strength parameters of M20 concrete (compressive and split tensile). For control concrete, IS method of mix design is adopted. Partial replacement of cement has been made with different percentage of RHA namely, 5%, 10% and 15%. Large range of curing periods starting from 7, 14 and 28 days are considered in the present study.

This paper presents the unusual engineering properties of coralline aggregates used for asphalt binder course production during the rehabilitation of  Zanzibar airport (Tanzania). The geotechnical and geomechanical properties of the coralline aggregates,  asphalt concrete mix design and the volumetric parameters achieved during mix design are discussed. Asphalt concrete production and the placing procedures are also discussed. Finally, the paper recommends the measures to be taken when using coralline aggregates for asphalt concrete production.T

Geopolymer results from the reaction of a source material that is rich in silica and alumina with alkaline liquid. It is essentially cement free concrete. This material is being studied extensively and shows promise as a greener substitute for ordinary Portland cement concrete in some applications. Research is shifting from the chemistry domain to engineering applications and commercial production of geopolymer concrete. It has been found that geopolymer concrete has good engineering properties with a reduced global warming potential resulting from the total replacement of ordinary Portland cement. The research undertaken at Curtin University of Technology has included studies on geopolymer concrete mix design, structural behavior and durability. This paper presents the results from studies on mix design development to enhance workability and strength of geopolymer concrete. The influence of factors such as, curing temperature and régime, aggregate shape, strengths, moisture content, preparation and grading, on workability and strength are presented. The paper also includes brief details of some recent applications of geopolymer concrete.

Pervious concrete is a tailored-property concrete with high water permeability which allow the passage of water to flow through easily through the existing interconnected large pore structure. This paper reports the results of an experimental investigation into the development of pervious concrete with reduced cement content and recycled concrete aggregate for sustainable permeable pavement construction. High fineness ground granulated blast furnace slag was used to replace up to 70 % cement by weight. The properties of the pervious concrete were evaluated by determining the compressive strength at 7 and 28 days, void content and water permeability under falling head. The compressive strength of pervious concrete increased with a reduction in the maximum aggregate size from 20 to 13 mm. The relationship between 28-day compressive strength and porosity for pervious concrete was adversely affected by the use of recycled concrete aggregate instead of natural aggregate. However, the binder materials type, age, aggregate size and test specimen shape had marginal effect on the strength-porosity relationship. The results also showed that the water permeability of pervious concrete is primarily influenced by the porosity and not affected by the use of recycled concrete aggregate in place of natural aggregate. The empirical inter-relationships developed among porosity, compressive strength and water permeability could be used in the mix design of pervious concrete with either natural or recycled concrete aggregates to meet the specification requirements of compressive strength and water permeability.

Concrete is the widely used material in the world. This automatically creates a huge demand for ingredient of concrete (Fine Aggregate, Coarse Aggregate and cement). From the environment point of view, the huge extraction of the aggregate creates depletion and manufacturing of cement causes pollution. This scenario affects the world's ecological balance. As a civil engineer, we have planned to replace the river sand which is widely used in construction by sea shell. Sea shell is the dead remain of the marine organism. We have replaced the sea shell after grinding it to the maximum size of 4.75 mm. The IS 10262-2009 was followed for the mix design of M20 grade concrete after that optimization of cement is done. Sea shell which is used in concrete confirming to the zone II as per IS 383-1970. Then cubes were casted for the 5 parts of partial replacement as 20%, 40%, 60 %, 80%, and 100 %. All the specimens are used for 7 & 28 days and tested for compressive, flexural and split tensile strength .We have observed the maximum strength is obtained for 80% replacement of sea shell.

Laporan ini berisi tentang teori dan tata cara pengujian untuk material bahan Beton, adapun jenis pengujian yang terdapat di dalam laporan ini yaitu : Analisa ayakan pasir & kerikil, Kadar lumpur pasir & kerikil, Berat jenis absorbsi pasir & kerikil, Keausan agregat dengan Los Angeles, Uji zat organik agregat halus, Waktu ikat semen, Berat jenis semen, Mix design beton K-175, Pembuatan benda uji beton K-175 dan Uji kuat tekan beton.

Now a days 3-Dimensional Printing (3DP) technology is used world widely and it can actually print each and every thing with the desired computer program. In Construction engineering the challenges are like availability of skilled man power, time constraint, cost effectiveness and complicated shapes etc. But with the help of an automated machine, the 3D printing technology, has huge potential to have faster and more accurate construction of complex and more laborious works. This technology can build three-dimensional (3D) objects by connecting layers of materials and can be applied to convert waste and by-products into new materials. The 3DP in concrete construction is increasing thanks to its freedom in geometry, rapidness, formwork-less printing, low waste generation, eco-friendliness, cost-saving nature and safety. This paper attempts to review the digital printing technology introduced in the construction industry and the also highlights the impact on concrete technology. It also discusses about the materials used in 3DP, mix design, various applications and challenges in the construction industry.

— The application of bituminous mixtures modified with rubber from scrap-tires require attention and care during mixing and compaction. Rubber modifies the properties because it reacts in the internal structure of bitumen at high temperatures changing the performance of the mixture (interaction process of solvents with binder-rubber aggregate). The main change is the increasing of the viscosity and elasticity of the binder due to the larger sizes of the rubber particles by dry process but, this positive effect is counteracted by short mixing times, compared to wet technology, and due to the transport processes, curing time and post-compaction of the mixtures. Therefore, negative effects as swelling of rubber particles, rebounding effect of the specimens and thermal changes by different expansion of the structure inside the mixtures, can change the mechanical properties of the rubberized blends. Based on the dry technology, different asphalt-rubber binders using devulcanized or natural rubber (truck and bus tread rubber), have been used to show how these defects occur and, at the same time, to solve the problems generated in dense-gap graded rubber modified asphalt concrete mixes (RUMAC) to enhance the stability, workability and durability of the compacted samples by Superpave gyratory compactor method. This paper specifies the procedures developed in the Department of Civil Engineering of the University of Palermo during September 2016 to March 2017, for characterizing the post-compaction and mix-stability of the one conventional mixture (hot mix asphalt without rubber) and two gap-graded rubberized asphalt mixtures, adopting the granulometric characteristic grading curve for rail sub-ballast layer, with nominal size of Ø22.4 mm of aggregates according European standard. Thus, the main purpose of this laboratory research is the application of ambient ground rubber from scrap tires processed at conventional temperature (20 ºC) inside hot bituminous mixtures (160-220 ºC) as a substitute for 1.5%, 2% and 3% by weight of the total aggregates (3.2%, 4.2% and, 6.2% respectively by volumetric part of the limestone aggregates of bulk density equal to 2.81 g/cm 3) considered, not as a part of the asphalt binder. The reference bituminous mixture was designed with 4% of binder and ±3% of air voids, manufactured for a conventional bitumen B50/70 at 160 ºC-145 ºC mix-compaction temperatures to guarantee the workability of the mixes. The proportions of rubber proposed are #60-40% for mixtures with 1.5 to 2% of rubber and, #20-80% for mixture with 3% of rubber (as example, a 60% of Ø0.4-2 mm and 40% of Ø2-4 mm). The temperature of the asphalt cement is between 160 and 180 ºC for mixing and 145 and 160 ºC for compaction, according the optimal values for viscosity using Brookfield viscometer and " ring and ball "-penetration tests. These crumb rubber particles act as a rubber-aggregate into the mixture, varying sizes between 0.4 mm and 2 mm). in a first fraction, and 2 and 4 mm as second proportion. Ambient ground rubber with a specific gravity of 1.154 g/cm 3 is used. The rubber is free of loose fabric, wire and other contaminants. It was found optimal results in real beams and cylindrical specimens with each HMA mixture reducing the swelling effect. Different factors as temperature, particle sizes of rubber, number of cycles and pressures of compaction that affect the interaction process are explained.

It is in the last five years that the stakeholders of concrete paving blocks (CPBs) are awakening to engineer the CPBs in Sri Lanka. Although large scale production of CPBs has already flourished in Sri Lanka, their adherence with stringent standards (both Sri Lankan and International) remains dubious. This reluctance to meet the performance and durability criteria according to codes of practices, curtails the life span of concrete block paved roads to a greater extent.

dari Semen sebagai bahan pengikat, Agregat halus (pasir) dan Agregat kasar (kerikil) sebagai bahan pengisi dan air sebagai bahan pencampur/pelumas. Bahan -bahan yang digunakan dalam campuran beton harus memenuhi syarat standar yaitu SK.SNI.5-04-1989.F AIR. Air yang digunakan untuk campuran beton harus bersih, tidak boleh mengandung minyak, asam alkali, zat organic atau bahan lainnya yang dapat merusak beton atau tulangan, sebaiknya dipakai air tawar yang dapat diminum.

Moisture damage is defined as loss of strength and durability of asphalt mixture due to moisture effect. Moisture also permeates making the mix more susceptible to damage during cyclic loading.  Various mechanism are involved in the process whose understanding is quint-essential for better mix design. A laboratory report of the same is provided.

The ingredient of concrete are mixed in different proportions, either by volume or by weight, the latter being more precise and scientific. Volume batching of concrete is not allowed by revised IS 456-2000 today and the common method of expressing the proportions of ingredients in concrete mix is in the form of parts or ratio of cement. The fine aggregate and coarse aggregate cement being taken as unity. Cubes are cured alternate wetting and drying condition (partially curing) average compressive strength of concrete cube 30.60 N/mm2. Which is approximately 60 % of target compressive strength. When cube are cost with no curing is carried out, the cube are cured in room, the average compressive strength of the cube at 28 days = 22.5 N/mm2. which approximately 58% of target which do not satisfied the requirement of target of M30 grade concrete , but it will satisfy the requirement of strength for M15 grade concrete. Therefore if the curing is not carried out site , grade of concrete used is M30 then the actual strength obtained at site. Sever cracks in concrete which affect scope serviceability, stability and safety. Which affect stability stiffness strength and seafty of the structure. Therefore curing is essential to gain the strength of concrete, for all structural element such as slab, beam. column and footing curing is to be carried out for 21 days IS code of PPC.

A mix design procedure for high-performance concrete mixes has been presented in this paper. Since rheological parameters and compressive strength are fundamental properties of concrete in two different stages of production, the correlation between rheological parameters and compressive strength has been used instead of using water-cement ratio versus compressive strength relationship. Water-cement ratio and aggregate volume to paste volume ratio has also been determined from rheological behavior and used in the mix design. In the proposed method, the designer is able to estimate rheological parameters like yield stress and plastic viscosity at the design stage for a given target strength, in addition to ingredients of concrete.

Satisfying the ever-growing demand of concrete aggregates poses a problem in many parts of the world due to shortage of natural sand. Moreover, to conserve natural resources and protect civil engineering infrastructures, there is a need to find alternative materials. Crushed stone sand has been identified as a potential substitute material for natural sand in making good quality concrete. The main objective of the present investigation is to determine an adequate mix design method and evaluate engineering properties of crushed limestone sand concrete mixtures in both the fresh and hardened sates. More than thirty concrete mixtures were examined. The results indicate that water demand and cement paste content in crushed sand concrete are generally higher than that used in similar conventional concrete. Good mechanical properties were obtained for concrete using crushed limestone sand as fine aggregates with a superplasticizer. However, a higher than normally used dosage of superplasticizer is required in these concrete mixtures and the optimum dosage of the superplasticizer needs to be determined for each cement and sand content.

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 granular distribution was minimized by the use of the approach based on the determination of the average diameter of the aggregates. This required the determination of a homothetic factor “k” similar for all concretes with different aggregate grading. Formulation of a self-compacting concrete passes initially by the determination of a sufficient quantity of paste allowing its flow without frictions between its aggregates and to balance the mixture by the quantity of water retained by the aggregates. The self-compacting concrete characteristics would come from those of the cement paste which composes it.

Portland cement is used by the construction industries, which is known to be a heavy contributor of carbon dioxide emissions and environmental damage. Adding of industrial wastes like demolished old concrete OF structures, silica fume (SF) fly ash (FA) as additional cementing materials (SCMs) could result in a substantial reduction of the overall Carbon dioxide trace marks of the final concrete product. Use of these additional materials in construction industry especially in the making of concrete is highly challenging. Remarkable research efforts are needed to study about the engineering properties of concrete incorporating such industrial wastes. Present research is an effort to study the properties of concrete adding industrial wastes such as demolished concrete, FA and SF The improvement of properties of RCA concrete with the incorporation of two ureolytic-type bacteria, Bacillus subtilis and Bacillus sphaericus to improve the properties of RCA concrete. The experimental investigations are carried out by experts evaluate the improvement of the compressive strength, capillary water absorption and drying shrinkage of RCA concrete adding bacteria. Seven concrete mixes are manufactured using Portland slag cement (PSC) partially changed with SF ranging from 0 to 30%. The mix proportions were obtained as per Indian standard IS: 10262-2009 with 10% extra cement when SF is taken as per the above the construction practice by experts. Optimal dosages of SF for maximum values of compressive strength, tensile splitting strength and flexural strength at 28 days are determined.

The market for medium strength (28)(29)(30)(31)(32)(33)(34)(35) concrete with high workability is recently increasing due to its qualitative and cost-saving advantages. This paper proposes a new mix design method for medium strength flowing concrete (FC) with low cement content. The proposed method determines the packing factor (aggregate content) first, and then fills binding paste containing fly ash and GGBS into the voids between aggregates to make concrete that has the desired workability and strength. Tests on slump, slump flow, and compressive strength were carried out and the results indicate that medium strength FC can be produced successfully using this method. Concrete mixtures designed by using the proposed method requires a small quantity of binder and is therefore very economical.

Due to growing environmental awareness, as well as stricter regulations on managing industrial waste, the world is increasingly turning to researching properties of industrial waste and finding solutions on using its valuable component parts so that those might be used as secondary raw material in other industrial branches. Although iron and steel slag is still today considered waste and is categorized in industrial waste catalogues in most countries in the world, it is most definitely not waste, neither by its physical and chemical properties nor according to data on its use as valuable material for different purposes. Moreover, since the earliest times of the discovery and development of processes of iron and other metals production, slag as by-product is used for satisfying diverse human needs, from the production of medicines and agro-technical agents to production of cement and construction element. Considering the specificity of physical and chemical properties of metallurgical slags and a series of possibilities for their use in other industrial branches and in the field of civil constructions, this report demonstrates the possibilities of using iron slag as partial replacement of sand in concrete. Iron and steel making slag are by products of the iron making and steelmaking processes. To date, these types of slag have been widely used in cement and as aggregate for civil works. The report presents an investigation of mechanical and durability properties of concrete by adding iron slag as replacement of sand in various percentages. The results show that the strength properties of concrete increase significantly when sand is partially replaced by iron slag.

In the present study, utilization of quartzite and Silico Manganese (Si-Mn) slag as an alternative for coarse aggregate was investigated. Studies were conducted on the physical and mechanical properties of the material. Compressive strength property under normal curing condition was studied. M25 grade experimental design was prepared in accordance with Indian standard Code IS: 10292-2000 methods. Cubes with a curing period of 28 days were used. Compressive strength results represent that utilization of quartzite has higher better than Si-Mn Slag. Physical and chemical properties represent that of quartzite had good resistance in crushing and impact tests.

Self compacting concrete recently developed concept in which the ingredients of the concrete mix are proportioned in such a way that it can flow under its own weight to completely fill the form work and passes through congested reinforcement without segregation and self consolidate without any mechanical vibration. In the present investigation M45 grade of SCC were developed using BIS method of mix design. To justify the fresh properties of the thus developed concrete slump flow test,T 50 cm test, J ring test, V funnel test, L box test and fill box test were conducted and fresh properties are checked as per EFNARC specifications. The standard sizes of 24 numbers of cubes,24 numbers of cylinders, and 24 numbers of beams were cast with and without confinement to determine the mechanical properties viz. compressive strength, split tensile strength, flexural strength and Modulus of Elasticity respectively. It is observed that the confinement of the concrete has increased the 28 days strength from 20 percent to 41.1 percent for different percentages of confinements and It peak stress and corresponding strain at peak stress increases with increase in percentage of confinements. Two analytical models were proposed to study the stress strain behavior of SCC under different confinements, It is observed that model based on L.S.Hsu and C.T.T.Hsu equation is closely agreeing with experimental results.

The aim of this study is to analyze the probability of using crushed stone dust as a substitute of fine aggregate (i.e. River Sand) in concrete at 3 MTPA Integrated Steel Plant Project by TATA Steel, Kalinganagar, Odisha, India. Accordingly, Trial Mix design of M25 grade concrete was carried out using crushed stone dust after fulfilling the physical properties as per the relevant standard. Several trials were conducted with crusher dust of different sources. Trials were also conducted with different admixtures. After conducting several trials, we have arrived at a workable proportion with crusher stone dust with higher compressive strength than the established mix design M 25 using river sand.

Bu çalışmada, beton maliyetinin en önemli unsuru olan çimentonun kullanımı için, basınç dayanımını fb=f(Su/Çimento) oranının fonksiyonu cinsinden belirleyen klasik yaklaşım, (fb/Mç) oranını maksimize eden optimum çimento miktarının (Mç)opt. karışımda kullanılması için bu çalışmada önerilen yeni yaklaşım ile tahkik edilmiştir. Çimento miktarının optimum kullanımı hem mikro ölçekte karışım tasarımında ekonomi sağlanması, hem de makro düzeyde daha az enerji tüketimi
anlamına gelmektedir.
In this study, a new approach has been proposed with the aim of rationalization of mix design. As it is known, cement quantity is the most important factor on mix cost. Proposed method in this study for estimation of optimum cement quantity Mc based on maximization of (fc/Mc) ratio has been statistically compared to classical relationships based on fc= f(water/cement ratio). Optimum cement utilization in mix indicates less energy consumption globally as well as less mix cost.

Pervious concrete is a tailored-property concrete with high water permeability which allow the passage of water to flow through easily through the existing interconnected large pore structure. This paper reports the results of an experimental investigation into the development of pervious concrete with reduced cement content and recycled concrete aggregate for sustainable permeable pavement construction. High fineness ground granulated blast furnace slag was used to replace up to 70 % cement by weight. The properties of the pervious concrete were evaluated by determining the compressive strength at 7 and 28 days, void content and water permeability under falling head. The compressive strength of pervious concrete increased with a reduction in the maximum aggregate size from 20 to 13 mm. The relationship between 28-day compressive strength and porosity for pervious concrete was adversely affected by the use of recycled concrete aggregate instead of natural aggregate. However, the binder materials type, age, aggregate size and test specimen shape had marginal effect on the strength-porosity relationship. The results also showed that the water permeability of pervious concrete is primarily influenced by the porosity and not affected by the use of recycled concrete aggregate in place of natural aggregate. The empirical inter-relationships developed among porosity, compressive strength and water permeability could be used in the mix design of pervious concrete with either natural or recycled concrete aggregates to meet the specification requirements of compressive strength and water permeability.

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 feasibility of using large rubber chunks from shredded tires as aggregates in coldmixes for road construction was investigated in this study. The research was directed toward development of a chunk rubber asphalt concrete mix design for low volume road construction using local aggregate, shredded tire rubber chunks and a cationic emulsion. A set of mixes using different combinations of chunk rubber content, emulsion content and fly ash content were tested. Marshall stability results of mixes with 10% Type C fly ash showed optimum emulsion contents of 6.8, 7.3 and 7.8% for 2, 4 and 6% rubber, respectively. The Marshall stability values decreased for increasing rubber contents. The target Marshall stability value of a suitable cold mix at 43ºC was required to be 2225 N. A mix with 10% Type C fly ash, 2% rubber and 7% emulsion showed an average Marshall stability value of 1600 N. Based on the Marshall stability results, some of these mixes appeared to be suitable as binder courses or stabilized drainable bases for low volume roads. If 9 kg of chunk rubber equivalent is produced per tire, then a one km long and 7.3 m wide low-volume road with a 100 mm thick base built with this mix can incorporate approximately 3350 tires. This application can minimize the scrap-tire waste problems of rural communities.

The aim of this paper is to evaluate the unconfined compressive strength of cemented peat in comparison to that of untreated peat. A laboratory study on the unconfined compressive strength of cemented peat is important in order to formulate a suitable and economical mix design for stabilized peat columns developed in deep peatland to support highway construction. To characterize the strength behavior of cemented peat, 14 test specimens of different mix designs of the cemented soil were prepared and tested in unconfined compression tests. The results revealed that test specimen with a mix design of 300 kg m-3 binder dosage by mass of wet peat (90 % MASCRETE and 10 %3 kaolinite in composition), 4 % calcium chloride by mass of binder, and 25 % siliceous sand by volume of wet peat gave the highest unconfined compressive strength of 413.0 kPa after 7 curing days in water. Such positive finding was largely attributed to the reactivity of the binder, calcium chloride and siliceous sand with wet peat. Thus, it can be concluded that high strength cemented peat can be produced when the MASCRETE and kaolinite stabilized peat admixture with siliceous sand acting as a filler, was activated by calcium chloride that accelerated the rate of cement hydration in the soil. © 2009, INSInet Publication.

www.ajbasweb.com/ajbas/2009/3850-3856.pdf

This is a report on an evaluation of the effect of local mix design of concrete on its compressive strength. In order to accomplish this research work, field survey was first undertaken with a well-structured questionnaire. This questionnaire was administered to the respondents who are directly involved in concrete production. Oral interview was also carried out in order to confirm the information given by the respondents concerning batching, mix ratio, etc. A study of contract document was undertaken with emphasis on specification of contract, bill of quantity and structural design in order to study how mix design is carried out in construction industry. Based on the information obtained from the respondents on how concrete is designed and specified in contract document and how such information is used in the production of concrete on construction sites, an experimental programme was set up in order to assess the extent of deviation from the normal. In the experiment, six different...

Abstract Using glass powder to manufacture eco-friendly self-consolidating concrete (SCC) has been developed and improved in recent years. While researchers have determined the effect of glass powder on rheological properties of the green concretes, the sensitivity of SCC to this powder content yet remains to be investigated. This study introduced the concepts of insensitive design, and subsequently, the ranges of water to powder ratio, sodium lignosulfonate plasticizer (LS), and glass powder were determined and optimized by the artificial neural network and particle swarm optimization, respectively. The results showed the possibility of producing SCC with the least possible sensitivity to water, glass powder, and plasticizer variations. The best water to cement ratio to design an insensitive SCC derived between 0.33 and 0.34, but the reduction in the compressive strength was inevitable for the augmented water-to-cement ratio. The effect of glass powder on alkali-silica reactions (ASR) and compressive strength was also investigated to clear the way for the incorporation of glass powder in SCC. The results indicated that the ASR reduced to 52% by substituting 30% glass powder.

"Various problems on the roads have been frequently observed on flexible pavements like: potholes, rutting, shoving etc. In hot and developing countries like India, roads are affected by severed problems mentioned above, due to the water presence in the pavement, heavy traffic load, excessive no. of vehicles. Literature review lightens up on solution of these problems by modification of bitumen. To lighten this process, several measures may be effective, such as, use of better quality materials like waste plastic, motor oil, crumb rubber. This study proposes the utilization of waste materials i.e. waste plastic, crumb rubber and motor oil and check their suitability to mitigate theses defects of cracking, rutting, pothole etc. Marshal stability method is chosen to determine the stability and flow value for bitumen mix design. Individual effects of polythene, crumb rubber and motor oil is analysed first by varying the percentage of same with optimum bitumen content. And comprehensive effect of these three material has been also observed and discussed by plotting the graphs and it is found that Bitumen (5.5 %), Crumb Rubber (8%), Waste Plastic (6%) and Motor Oil (2%) gives highest stability and other properties values within the range given in MORTH. It is expected that this study would be useful to researchers and consultancies to construct the roads economically and long lasting servicing. Vineet Jain | Utkarsh Nigam | Lokesh Gupta""An Experimental Study on Modification of Dense Graded Bituminous Mix Design"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-4 , June 2017, URL: http://www.ijtsrd.com/papers/ijtsrd127.pdf
Article URL: http://www.ijtsrd.com/engineering/transport-engineering/127/an-experimental-study-on-modification-of-dense-graded-bituminous-mix-design/vineet-jain"

In recent decades, the utilization of mineral and chemical admixtures in concrete technology has led to changes in the formulation and mix design which has, in turn, made the concretestrongerandmoredurable.Lightweightconcrete(LWC)isanexcellent solution intermsofdecreasingthedeadloadofthestructure,whileself-compacting concrete(SCC)easesthepouringandremovesconstructionproblems.Combiningthe advantages of LWC and SCC is a new field of research. Considering its light-weight of structure and ease of placement, Light-weight self-compacting concrete (LWSCC) maybe the answertotheincreasingconstructionrequirementsofslenderandmoreheavily reinforcedstructuralelements.Twentyonelaboratoryexperimentalinvestigationsonthe mix proportion,densityandmechanicalpropertiesofLWSCChavebeenpublishedinthe last 12yearsandtheseareanalyzedinthisstudy.Thecollectedinformationisusedto investigatethemixproportionsincludingthechemicalandmineraladmixtures,light weight and normal weight aggregates, fillers, cement and water. Analyzed results are presentedintermsofstatisticalexpressions.Itisveryhelpfulforfutureresearchtochoose the propercomponentswithdifferentratiosandcuringconditionstoattainthedesired concrete gradeaccordingtotheplannedapplication.

Pervious concrete is a tailored-property concrete with high water permeability which allow the passage of water to flow through easily through the existing interconnected large pore structure. This paper reports the results of an experimental investigation into the development of pervious concrete with reduced cement content and recycled concrete aggregate for sustainable permeable pavement construction. High fineness ground granulated blast furnace slag was used to replace up to 70 % cement by weight. The properties of the pervious concrete were evaluated by determining the compressive strength at 7 and 28 days, void content and water permeability under falling head. The compressive strength of pervious concrete increased with a reduction in the maximum aggregate size from 20 to 13 mm. The relationship between 28-day compressive strength and porosity for pervious concrete was adversely affected by the use of recycled concrete aggregate instead of natural aggregate. However, the binder materials type, age, aggregate size and test specimen shape had marginal effect on the strength-porosity relationship. The results also showed that the water permeability of pervious concrete is primarily influenced by the porosity and not affected by the use of recycled concrete aggregate in place of natural aggregate. The empirical interrelationships developed among porosity, compressive strength and water permeability could be used in the mix design of pervious concrete with either natural or recycled concrete aggregates to meet the specification requirements of compressive strength and water permeability.

This paper presents a focused study on properties of porous concrete to widen its application to structural engineering. Mechanical properties like compressive strength, indirect tensile strength, flexural strength and physical properties like density, permeability and porosity are studied. To determine those parameters, twenty-seven cubes, cylinders and prisms were tested. Also, three polymer impregnated porous concrete slabs were tested under pure bending moment to study the efficiency of selected resin to integrate particle of concrete to achieve a new generation in using porous concrete in structural engineering. Three different cement content specimens of porous concrete were considered, studied cement contents are 200 kg/m 3 , 300 kg/m 3 and 400 kg/m 3. The results show that, increasing the cement content can increase the compressive strength, indirect tensile strength and flexural strength. Density of porous concrete is less than conventional concrete by 21% but permeability factor recorded higher value compared to conventional concrete by sixteen times. Increasing the cement content has no significant effect on either ultimate load or maximum deflection of polymer impregnated porous concrete slabs but the results recorded an achievement to use this concrete in structural engineering applications and give an easy way to cast special concrete like polymer concrete without special tools.

Satisfying the ever-growing demand of concrete aggregates poses a problem in many parts of the world due to shortage of natural sand. Moreover, to conserve natural resources and protect civil engineering infrastructures, there is a need to find alternative materials. Crushed stone sand has been identified as a potential substitute material for natural sand in making good quality concrete. The main objective of the present investigation is to determine an adequate mix design method and evaluate engineering properties of crushed limestone sand concrete mixtures in both the fresh and hardened sates. More than thirty concrete mixtures were examined. The results indicate that water demand and cement paste content in crushed sand concrete are generally higher than that used in similar conventional concrete. Good mechanical properties were obtained for concrete using crushed limestone sand as fine aggregates with a superplasticizer. However, a higher than normally used dosage of superplast...

SCC can be made from any of the constituents that are generally used for structural concrete. In the mix design of SCC, the relative proportions of key components are generally considered by volume rather than by mass. On the basis of these proportions, a simple tool has been designed for self compacting concrete (SCC) mix design. In this paper, this tool has been evaluated with a SCC mix having 28% of coarse aggregate content, 35% replacement of cement with class F fly ash, 0.36 water/cementitious ratio (by weight) and 388 litre/m 3 of paste volume. Crushed granite stones of size 20mm and 10mm are used with a blending 60:40 by percentage weight of total coarse aggregate. Detailed steps used in this tool are discussed in this study. This tool can also be used for self compacting mortar (SCM) design. It is practically seen that this simple tool is very much useful for the mix design of SCC with or without blended cement and with or without coarse aggregate blending..

To build environmentally sustainable structures, especially in developing countries, the possibility of using some agricultural wastes and industrial by-products from different industries as construction materials will be highly desirable and has several practical and economic advantages. Oil palm shell (OPS) is a form of agricultural solid waste in the tropical regimes. Research over the last two decades shows that OPS can be used as a lightweight aggregate for producing structural lightweight aggregate concrete. The density of OPS concrete is around 20-25% lower than normal weight concrete. Generally, mechanical properties of OPS concrete are slightly lower than the other types of lightweight aggregate concrete. It seems that from the summary and analysis of the existing information concerning OPS concrete and comparing it with other lightweight aggregate concrete it appears that significant achievements can be attained.

Design of concrete mixtures is the process of selecting the most economical and practical proportions of all the ingredients to produce quality concrete. Because of the nature of the mix design process and all the heuristic knowledge that is associated with it, concrete mix design lends itself well to a knowledge-based application. This paper describes a prototype knowledge-based system called HPCMIX that can be used to load the experimental data, develop several statistical models to determine the responses, evaluate the predicted models, and predict the 28 days strength and slump. It can also be used to design HPC mix proportions that are subjected to specified constraints (e.g. strength and slump). It is capable of selecting proportions of mixing water, cement, supplementary cementitious materials, aggregates and superplasticizer, with consideration being given to the effects of air content as well as water contributed by superplasticizer and moisture conditions of aggregates. As most of knowledge-based systems, this system has explanation facilities, can be incrementally expanded, and has an easy to understand knowledge base. The system was tested on a sample project. The system's selection of the concrete proportions compared favourably with the expert's selection. The system is very useful for civil engineering students as well as practicing engineers.

Self compacting concrete recently developed concept in which the ingredients of the concrete mix are proportioned in such a way that it can flow under its own weight to completely fill the form work and passes through congested reinforcement without segregation and self consolidate without any mechanical vibration. In the present investigation M45 grade of SCC were developed using BIS method of mix design. To justify the fresh properties of the thus developed concrete slump flow test,T 50 cm test, J ring test, V funnel test, L box test and fill box test were conducted and fresh properties are checked as per EFNARC specifications. The standard sizes of 24 numbers of cubes,24 numbers of cylinders, and 24 numbers of beams were cast with and without confinement to determine the mechanical properties viz. compressive strength, split tensile strength, flexural strength and Modulus of Elasticity respectively. It is observed that the confinement of the concrete has increased the 28 days strength from 20 percent to 41.1 percent for different percentages of confinements and It peak stress and corresponding strain at peak stress increases with increase in percentage of confinements. Two analytical models were proposed to study the stress strain behavior of SCC under different confinements, It is observed that model based on L.S.Hsu and C.T.T.Hsu equation is closely agreeing with experimental results.

The aim of this paper is to evaluate the unconfined compressive strength of cemented peat in comparison to that of untreated peat. A laboratory study on the unconfined compressive strength of cemented peat is important in order to formulate a suitable and economical mix design for stabilized peat columns developed in deep peatland to support highway construction. To characterize the strength behavior of cemented peat, 14 test specimens of different mix designs of the cemented soil were prepared and tested in unconfined compression tests. The results revealed that test specimen with a mix design of 300 kg m binder dosage by mass of wet peat (90 % MASCRETE and 10 %-3 kaolinite in composition), 4 % calcium chloride by mass of binder, and 25 % siliceous sand by volume of wet peat gave the highest unconfined compressive strength of 413.0 kPa after 7 curing days in water. Such positive finding was largely attributed to the reactivity of the binder, calcium chloride and siliceous sand with wet peat. Thus, it can be concluded that high strength cemented peat can be produced when the MASCRETE and kaolinite stabilized peat admixture with siliceous sand acting as a filler, was activated by calcium chloride that accelerated the rate of cement hydration in the soil.

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.