Substitution Of Coarse Aggregate Research Articles

Kajian Kuat Tarik Belah pada Beton Variasi Limbah Granit Sebagai Substitusi Parsial Agregat Kasar

The development of concrete making technology has developed rapidly nowdays, the innovations in terms of material use and workmanship. The implementation of construction work carried out today pays attention to aspects of strength, rigidity, and high durability, as well as sustainability. To support these two things, research can be carried out on making concrete using granite waste. The research method used in this study is an experimental method. The concrete mix design uses variations of granite waste with successive levels of 0%, 15%, 30%, and 45%. The test specimen used for tensile strength testing is cylindrical with a diameter of 15 cm and a height of 30 cm, the test uses 12 specimens where each variation uses 3 specimens. The test is performed when the specimen has reached the age of 28 days. The test specimen tested has met the planned compressive strength requirements at a concrete life of 28 days where the results are greater than 20 MPa. Results of testing the tensile strength of concrete variations of granite waste as a partial substitution of coarse aggregate with variations of granite waste of 0%, 15%, 30%, and 45% respectively; 2.43 MPa; 2.50 MPa; 2.97 MPa; and 2.78 MPa.

Mechanical Damage and Freeze–Thaw Damage of Concrete with Recycled Brick Coarse Aggregate

The influence of different recycled brick coarse aggregate (RBA) substitution rates on the mechanical performance and frost resistance of concrete was observed. The test findings revealed that RBA deteriorated the compressive and flexural properties in concrete and improved the tensile properties and plasticity in concrete to some extent. The frost resistance of concrete can be effectively improved by adding RBA. The influence degree of the RBA concrete frost resistance factor was quantified by gray entropy correlation theory, and the gray entropy correlations between freezing and thawing cycles, natural coarse aggregate substitution rate, recycled brick aggregate substitution rate, and freezing and thawing damage value (DN) were 0.9979, 0.9914, and 0.9876, respectively. Moreover, the freezing and thawing damage model about GM(1, 1) theory was developed (R2 > 0.87), which can better predict the freezing and thawing damage of RBA concrete. The damage mechanism of RBA concrete during freezing and thawing was revealed.

Kepah Shell Waste as A Coarse Aggregate Substitution Material on Concrete Mixture

This research uses kepah shell waste as a substitute for coarse aggregate. The purpose of this study is to determine the value of slump and compressive strength values in concrete variations. Variations of concrete consist of normal concrete, mixed shells of waste concrete with 5%, 10%, and 15% substitution of coarse aggregate. The concrete maintenance period was carried out for 7 days, 14 days, and 28 days. The results of the slump value research show that the lowest slump value is normal concrete, while the highest slump value is concrete with a mixture of 15% kepah shell waste. For the results of the compressive strength value, the highest compressive strength value is concrete with a mixture of 5% kepah shell waste. For the most economical cost with high quality of concrete compression strength is the concrete mixture with 5% of kepah shell waste. The greater the percentage of kepah shell waste, the cheaper the concrete price, but higher percentage of kepah shell waste will result a decrease in the quality of concrete.

Use Crumb Rubber Chips in Partial Substitution of Coarse Aggregate While Preparing Concrete

Abstract: The purpose of this experimental investigation is to examine the behaviour features of rubberized concrete, which has coarse aggregate in place of some of the tyre rubber. Over 270 million scrap tyres are thought to be produced annually. One of the main problems in India is the disposal of discarded tyres in landfills, which is the responsibility of local governments and municipalities. Because it is not biodegradable, there are serious concerns to human health, the environment, and fire. The most promising uses of tyres in engineering are as aggregates for asphalt and concrete, artificial reefs, and erosion management, aside from gasoline obtained from tyres. Concrete's characteristics could be greatly improved in a variety of ways by using recycled tyre rubber as part of the aggregate. One of the most often used building materials is concrete. Because of this, the building sector is constantly looking for new applications and uses for its products, as well as ways to improve them while keeping costs down. The reference concrete specimen is made of M30 grade concrete. Rubber chips from scrap tyres have been utilised in place of traditional coarse aggregate as coarse aggregate. This will enable the efficient and widespread handling of rubber tyre waste in addition to enabling the sustainable use of the aggregates that are already accessible to us. After separating the rubber tyre waste into coarse chips, this tyre crumb aggregate is applied in increments of 5%, 10%, or 15% to replace the coarse aggregate. In order to determine the best way to employ crumb rubber as coarse aggregate in concrete, this study assessed the workability and compressive strength of rubberized concrete

Damage constitutive model of polypropylene-fibre-reinforced recycled aggregate concrete

Adding polypropylene fibre (PPF) to recycled aggregate concrete (RAC) not only improves performance but also has economic benefits. The effects of single-blend and double-blend micro- and macro-PPFs in RAC specimens were studied. Micro- and macro-PPFs were used to design and produce 30 groups of PPF-reinforced RAC specimens with 0%, 25% and 50% coarse aggregate (CA) substitution rates. Controlling the fibre mixing proportions, the stress–strain curve, elastic modulus, peak strength, peak strain and acoustic emission amplitude–frequency extremum (AFE) of each group of specimens were obtained. The elastic modulus and peak stress of specimens without PPFs decreases gradually with an increase of the CA substitution rate. However, there was a certain increase in elastic modulus and peak stress when PPFs were added. A damage constitutive model for PPF-reinforced RAC was established. By fitting this model, it was found that although the elastic modulus and peak stress of the RAC specimens increased by a certain extent, the fitting parameters of RAC were greater than those of ordinary concrete and the RAC post-peak strength was lower. The evolution law of acoustic emission AFE of PPF-reinforced RAC was studied. It was found that the cumulative AFE of RAC with PPF was larger, indicating that the PPFs limited crack propagation and increased the fracture energy.

ANALYSIS OF THE EFFECT OF COARSE AGGREGATE PARTIAL SUBSTITUTION WITH GRANITE FRAGMENTS IN THE COMPOSITION OF CONCRETE MIXTURE MATERIALS TOWARD CONCRETE COMPRESSIVE STRENGTH

The concrete basic composition can be modified by using alternative materials for coarse aggregate, fine aggregate, or modifying the type of sand. In this study, destructive method testing was applied to find the compressive strength of concrete that was mixed with coarse aggregate admixture material from granite waste that was combined with natural aggregate and then compared with normal concrete.The sands added to the mixture originated from the Serayu River and Mount Merapi. To create concrete with a planned quality of fc’ 30 Mpa, three types of test objects are created. The first is unmixed concrete (0% admixture), the second and the third are uses granite waste as coarse aggregate substitution as much as 50%, and 100%.The test objects were then tested for compressive strength in 7 days and 28 days. The seven (7) days test showed that maximum compressive strength of 22,23 Mpa was produced by a mixture of Mount Merapi and coarse aggregate substitution of 50% granite waste. The use of Mount Merapi sand and Serayu River sand in all substitution compositions of granite waste shows that concrete compressive strength that uses Mount Merapi sand is better than in the mixture that uses Serayu River sand.

A Comprehensive Investigation of Performance Characteristics, Mechanical Properties and Durability Parameters of Self-compacting Concrete Containing Iron Slag as Coarse Aggregate

In this paper, iron slag is used as partial coarse aggregate substitution in Self-compacting concrete (SCC). The SCC samples tests were conducted after 28 days of water curing for samples with 0%, 10%, 20%, 30%, 40%, 50%, and 60% iron slag as coarse aggregate substitutes. This paper evaluates slump flow, V-funnel, L-box, compressive strength, flexural strength, splitting tensile strength, surface water absorption, capillary water absorption, electrical resistance, acid resistance, and ultrasonic pulse velocity (UPV) of concrete samples. Furthermore, scanning electron microscopy (SEM) of samples was investigated for evaluating cement paste microstructure. Samples containing 20%, 60%, and 60% iron slag as coarse aggregate substitute have higher compressive, flexural, and splitting tensile strength than control samples (about 18.4%, 28.6%, and 16.9% higher, respectively). In addition, using 10%, 20%, 30%, and 40% iron slag as coarse aggregate increased the compressive strength. Moreover, incorporating iron slag as a coarse aggregate decreased the mass loss of samples which were exposed to the acid environment compared to control specimens. Using iron slag as partial coarse aggregate substitution reduced the porosity of the cement matrix compared to control samples (based on SEM images).

Experimental investigation on utilization of substitute building materials in concrete using neural networks

The replacement of cement with sugarcane bagasse ash in concrete is considered due to its rich properties of projecting pozzolanic activity. The availability of aggregates is becoming scarce as a result of the non-renewable characteristic of fine and coarse aggregates. The construction waste end products like demolishing waste also cause the problem of improper disposal. Hence a majority of the construction industries have preferred the usage of construction and demolition (C&D) waste as a replacement for coarse aggregate. Substitution of coarse aggregates by construction and demolition waste and fine aggregates by iron slag ash is considered. The Taguchi method is adopted for the determination of mix combinations. This paper focuses on determining the properties of concrete having pozzolanic properties by replacing the cement with sugarcane bagasse ash (SBA), coarse aggregate with demolished building waste (DBW), and Fine aggregate with iron slag ash (ISA). The experimental investigation proved that SBA, DBW and ISA have a potential sign to be used as an alternative sustainable building material. From the comparative analysis of experimental results with ANN, it is revealed that the concrete show an acceptable prediction of physical and strength properties.

PEMANFAATAN BAHAN LOKAL BAMBU MAYAN SEBAGAI BAHAN SUBSTITUSI ANGREGAT PADA BETON

Bamboo is a plant that can be found around us, especially in rural areas. Bamboo is an environmentally friendly building material compared to conventional building materials. In addition to being easily accessible, cheap, and lightweight, bamboo also possesses considerable strength. There have been numerous studies on the use of bamboo, but in this research, bamboo is utilized as a substitute material for coarse aggregates. The planned compressive strength is for concrete with a compressive strength of K250 (20.75MPa) with substitution proportions of 30%, 50%, and 100%, which will be compared with normal concrete. In this study, it is expected to determine the proportion of substitution of coarse aggregates in concrete using bamboo. Based on the tests conducted, ranging from testing concrete-forming materials to compressive strength tests, the compressive strength obtained for normal concrete (0%) at 28 days is 26 MPa. Meanwhile, the compressive strength for concrete with a 30% substitution proportion is 26 MPa, 50% proportion is 13 MPa, and 100% proportion is 9 MPa. Thus, it can be concluded that the greater the percentage of concrete substitution, the lower the compressive strength obtained.

A Study of Acoustic Emission Based RA-AF Characteristics of Polypropylene Fiber-Reinforced Recycled Aggregate Concrete Under Uniaxial Compression

In order to research the acoustic emission characteristics of polypropylene fiber-reinforced recycled aggregate concrete under uniaxial load, 20 groups of test specimens with a coarse aggregate substitution rate of 25 % and 50 % are designed and fabricated to conduct the acoustic emission test under uniaxial compression, and the evolution laws of the acoustic emission b-value, the cracking modes and the acoustic emission RA-AF moving averages with time are studied. The laws of influence of the coarse aggregate substitution rate and coarse-fine polypropylene fiber on the acoustic emission b-value of RAC are discussed. The K-means clustering method is adopted for two-dimensional clustering analysis of the shear cracking and tensile cracking, and then the SVM is used to obtain the boundary between the two types of clusters. The time distribution laws of shear cracking and tensile cracking of the polypropylene fiber-reinforced recycled aggregate concrete are analyzed. The changes in the moving averages of RA and AF of RAC test specimens with time are studied, and the research indicates that as the RA value decreases, the shear cracking gradually reduces and the tensile cracking gradually increases and dominates.

Waste Plastic Induced in Self Compacting Concrete to Avoid Plastic Pollution

Abstract: In this present study the plastic aggregate obtained from E-waste is used as a partial replacement of coarse aggregate in self-compacting concrete. An experimental investigation on the fresh, hardened characteristics of concrete using M40 grade of Self compacting concrete are carried out by casting standard concrete with various volume fractions of plastic aggregate such as 0%, 10%, 20%, 30%, 40%, 50% to determine optimal dosage. The fresh properties of SCC reveal that the workability of concrete are improved by using plastic aggregate. Strength properties such as compressive strength shows that up to 30% substitution of coarse aggregate there is no major change in compressive strength as compared to normal concrete. Beyond that there is drop in compressive strength for 50% replacement of coarse aggregate by plastic aggregate. Split tensile strength, Flexural strength and Young modulus of concrete increases for 10% plastic aggregate. Beyond that strength decreases upto 50% replacement. Impact strength decreases for all replacement levels.

Utilization of Steel Slag Waste as a Substitute for Coarse Aggregate in Concrete Mixture

Concrete is a crucial building material used for various structural components in buildings. It consists of cement, water, fine aggregate (sand), and coarse aggregate (gravel). This research focuses on the development of steel slag concrete as a replacement material for coarse aggregate, aiming to appropriately utilize steel slag waste, which poses environmental and health concerns. The study investigates the effect of substituting steel slag for coarse aggregate on the compressive strength of concrete and determines the optimal steel slag to normal concrete ratio. Concrete samples aged for three, seven, and 28 days were prepared using SNI 7656:2012, incorporating different proportions of steel slag as a substitute for coarse aggregate. Results indicate that variations of 20%, 40%, and 60% show improvements in comparison to normal concrete after three and seven days of curing. However, the variations of 80% and 100% are less commonly used than standard concrete. The increase in compressive strength of steel slag concrete aged 28 days, compared to normal concrete, for variations of 20%, 40%, and 60% is 1.54%, 3.00%, and 6.57%, respectively, while the reduction for variations of 80% and 100% is 7.93% and 18.80%. Based on the results, steel slag concrete with a 60% substitution of coarse aggregate exhibits the optimal compressive strength ratio in the mixture.

Influence Substitution of Tabas Stone Waste which Coated Polyester Resin to Concrete Compressive Strength

The need for the use of concrete raw materials is increasing in line with the increase in the use of concrete in construction. The availability of concrete raw materials is dominated by the exploitation of natural resources, namely components of cement, sand and crushed stone or gravel. If the availability of this material is exploited in excess, it will have an impact on environmental damage. On the other hand, many stone crafts for decoration and building ornaments in Bali also utilize tabas stone which is also exploited from nature, where the processed rock leaves a lot of waste that is disposed of without any wise processing actions. Tabas stone waste management is expected to maximize the utilization of natural resources and also reduce environmental pollution caused by the disposal of tabas stone waste that is not managed properly. This research is expected to provide an alternative to maximize the use of tabas waste as a partial substitution of crushed stone or gravel as coarse aggregate in concrete mixtures. The porous structure of tabas stone and the high level of water absorption in the concrete mix can reduce the compressive strength of the concrete. Steps to reduce water absorption in tabas stone are carried out by maximally closing the pores using a polyester resin coating. The study was carried out by making normal concrete mixture objects according to SNI 03-2834-2000. The percentage of substitution of crushed stone with waste stone that is coated with polyester resin is 0%, 25%, 50%, 75%, 100% of the required weight of coarse aggregate. The compressive strength of the concrete will be tested at the age of 7 and 28 days using a cylindrical specimen measuring 150x300mm. Test results in the laboratory showed that the coating of tabas stone using polyester resin was able to reduce the level of water absorption from 9.96% to 3.24% or 67.5% compared to tabas stone that was not coated with polyester resin. The optimum compressive strength of coarse aggregate substitution using tabas was obtained at variations of 50% crushed stone 50% tabas stone at the age of 7 days and 28 days, respectively, reaching 15.06 MPa and 21.55 MPa.

Road use and electrothermal performance of graphene-conductive asphalt-recycled pervious concrete under severe cold environment

Conductive-asphalt-recycled pervious concrete alleviates the urban “heat island effect” and “rain island effect” to realize the resourceful and efficient use of waste concrete and also reduces the probability of urban snow and ice disasters to ensure the safety of winter operation of asphalt pavements in cold areas. This study presents a theoretical and technical basis for ensuring the winter operational safety of asphalt pavements in cold regions. First, we compound graphene and carbon fiber as conductive phase materials and prepare graphene-conductive asphalt-recycled permeable concrete using recycled coarse aggregates with straight top and bottom holes. Then, we analyzed the electrical conductivity, road performance, and electrothermal performance of the specimens prepared using different recycled coarse aggregate substitution rates under different snowfall levels to determine their snow melting efficiency and verify their application in cold regions. The results indicate that the quality of the recycled aggregates is high, the optimal conductive filler ratio is 0.3% polyacrylonitrile-based carbon fiber and 1.5% graphene by mass of asphalt, and the resistivity of the specimens is only 3.2 Ω·m. Moreover, the conductivity and road performance of the graphene-conductive asphalt-recycled concrete decreases with an increase in the replacement rate of the recycled coarse aggregate, and the artificially prefabricated upper and lower through holes affect the conductivity of the specimens to a certain extent. Further, the graphene-conductive asphalt-recycled pervious concrete shows excellent snow melting potential, and as the required snow melting thickness and snow melting time increase, the effect of pervious asphalt slabs for snow melting efficiency becomes more significant. Moreover, when the replacement rate of the recycled concrete aggregate is within the range of 0–50%, it can be completed in 2–3 h under different snowfall levels of snow melting requirements.

Predicting Strength Properties of High-Performance Concrete Modified with Natural Aggregates and Ferroslag under Varied Curing Conditions

High-performance concrete (HPC) is obtained by inclusion of mineral admixtures like silica fumes and fly ash to the normal concrete. Consumption of natural materials such as sand, natural aggregates, and limestone produces environmental degradation. Similarly, industrial by-products such as fly ash, silica fume, and ferro slag need to be safely disposed of without negatively impacting the environment. The problem being addressed in this study is the need to develop high-performance concrete (HPC) that is durable and environmentally friendly. In recent years, the use of natural aggregates and ferro slag as partial replacements for traditional aggregates has gained attention as a sustainable alternative in the production of concrete. However, there is limited research on the effect of these materials on the mechanical and durability properties of HPC under varied curing conditions. In this current research, high-performance concrete of M60 grade with partial substitution of coarse aggregate with ferro slag aggregate was formed as per the recommendations of the American Concrete Institute with the inclusion of fly ash and silica fume. Natural coarse aggregate was partly substituted by ferro slag aggregate in proportions from 0% to 40%. Partial substitution of cement was made with 15% of fly ash and 10% of silica fumes. Specimens of normal concrete mix (MF0) and modified ferro slag aggregate concrete mix (MF20, MF30, and MF40) were prepared and subjected to acid test, sulphate test, and alternate wet and drying tests to assess the compressive strength of the concrete mixes. Central composite design (CCD) of RSM modelling was adopted to recommend a regression model to forecast the compressive strength of concrete under wetting drying test, acid test, and sulphate attack. Further, natural aggregate, ferro slag, and duration of curing were considered as basic variables to suggest the model. Regression models for response data were evaluated using analysis of variance (ANOVA) and Pareto charts. The results show that the mix MF30 (30% substitution of natural aggregate by ferro slag aggregate) had higher compressive strength. The residual compressive strength at 270 days under alternate wetting and drying, acid attack, and sulphate attack was obtained as 62 MPa, 62.50 MPa, and 66.50 MPa, respectively. Similarly, the percentage loss of weight was obtained as 12.92%, 12.22%, and 6.60% for alternate wetting and drying, acid attack, and sulphate attack, respectively. The findings of the analysis of variance (ANOVA) indicate that the most significant factors influencing the variables C S W D , C S A T , and C S S T are natural aggregate, ferro slag, and curing period. The regression models for C S W D , C S A T , and C S S T are extremely significant, as shown by the ANOVA and Pareto chart analyses.

The Effects of Steel Fiber Types and Volume Fraction on the Physical and Mechanical Properties of Concrete

Different types and amounts of steel fibers have varying effects on the improvement of concrete’s mechanical properties. In order to identify the most suitable steel fiber types for the practical production of prefabricated pavements and derive a formula to predict and evaluate the mechanical properties based on steel fiber volume fraction, this study conducted experimental research on the physical mechanical properties of concrete using the method of equal volume substitution of coarse aggregate. The influence of steel fiber type and volume fraction on the microstructure and failure mechanism of steel fiber reinforced concrete (SFRC) was analyzed through electron microscopy scanning. The mechanical properties of plain concrete were used as benchmark. The results showed that when the steel fiber volume fractions were 0.6% and 1.5%, the bending and split tensile strengths of milled steel fibers were 3.1% higher than those of hooked-end steel fibers and the compressive strength of SFRC was significantly increased by 13.5%. The comprehensive mechanical properties of wave-shaped steel fibers were inferior to the first two types. Considering the requirements of SFRC in engineering, milled steel fibers are more suitable to be concrete components. This is because the tangling property of the hooked-end steel fibers makes them difficult to be shaped. In contrast, the smooth surface of milled steel fibers exerts a smaller impact on the forming of specimen and they are more economical. The mechanical properties of SFRC improve as the volume fraction of steel fibers increases from 0% to 2%, but start to decline when the volume fraction exceeds 2%. A volume fraction of 0.6% for steel fibers is sufficient to meet the standard for bending and tensile strength in heavy-duty concrete pavements. Finally, the relationship expressions between the compressive strength, flexural strength, and split tensile strength of SFRC and the steel fiber volume fraction were obtained through fitting the experimental data using Origin software.

Investigating the fresh and mechanical properties of wood sawdust-modified lightweight geopolymer concrete

Geopolymer concrete has developed as a potential alternative to ordinary Portland cement-based concrete, wherein various industrial by-products have been converted as beneficial spin-offs. Apart from appropriate compressive strength in the construction sector worldwide, the durability, sound absorption, thermal conductivity, and weight of concrete are also major concerns. Lightweight geopolymer concretes have gained attention because of their superior strength, durability, lower environmental impact, and sustainable characteristics. In this view, the current study examined the feasibility of using sawdust as a natural fine and coarse aggregate substitution in fly ash (FA)-granulated blast furnace slag (GBFS) based geopolymer concrete. Four mixes with a different percentage of sawdust (25, 50, 75, and 100) substituting natural aggregate were designed to examine the effects of sawdust on fresh and hardened features of geopolymer concrete compared to those conventional FA-GBFS-based geopolymer concrete with natural aggregate. Sodium silicate (NS) and sodium hydroxide (NH) (with NS/NH ratio of 0.75) were utilized to dissolve the alumina silicate from FA and GBFS. Informational models were developed using an experimental dataset to estimate the compressive strength of geopolymer concrete mix designs. Besides, using the weight of the developed network, a global sensitivity (GS) analysis was developed to identify the sensitivity of compressive strength to the waste sawdust content. Test results confirmed that by substituting natural aggregate with 100% sawdust, there was around a 35% decrease in compressive strength. Nevertheless, the sound absorption coefficient was increased by an average of 38% in frequencies range between 1800 and 2500 HZ, and thermal conductivity decreased by around 4.5 times once the natural aggregate was substituted by 100% sawdust.

Mechanical Behaviour of Self-Compacting Concrete Using Ceramic Waste

The use of Self Compacting Concrete (SCC) which has high workability is the current choice to facilitate casting work so that it can pass through denser reinforcement areas without compaction. The rapidly increasing demand for concrete can cause damage to nature due to the overexploitation of minerals used for concrete such as crushed stone and lime. Construction waste can be an alternative to substitute the use of natural coarse and fine aggregate and an option to reduce gas emissions resulting from processing construction materials such as crushing work and cement production. Moreover, it can increase the efficiency of waste. In this study, ceramic waste is used as a substitute for coarse aggregate, which has the same characteristics as natural aggregate and is usually only dumped in landfill. This study aims to determine the mechanical behavior of SCC using ceramic waste as coarse aggregate substitution with a diameter of 9,52 mm. The mix design uses the Indonesian standard, SNI 7656-2012 with a maximum coarse aggregate size of 9.52 mm and Sika viscocrete 1003 as a superplasticizer. The concrete specimen is 15 cm in diameter and 30 cm in height cylinder of as many as 25 specimens. Design concrete strength is f’c = 25 MPa at 28 days old. The variation of the coarse aggregate substitution of ceramic waste is 0%, 25%, 50%, and 75%, and the 1.5% superplasticizer by the weight of cement. It is obtained that the maximum compressive strength of SCC is a variation of 50% ceramic waste, 25.98 MPa. It showed that the compressive strength did not experience a significant increase, which was only 0.06% increase from the design concrete strength. The stress value also showed a slight increase of 50% ceramic waste variation at 9.42 MPa with a 0.00254 strain value. The modulus of elasticity of concrete at maximum stress is 30,045.89 MPa. It can be concluded that ceramic waste can be used as a substitute for coarse aggregate in SCC. Although it cannot significantly increase the strength of the concrete as well as its stress and modulus of elasticity, ceramic waste substitution for natural aggregate in concrete can minimize the exploitation of minerals in nature and the strength also can exceed the design concrete strength.

Numerical analysis of construction and demolition (C&D) waste-based geopolymer concrete beams with partially replaced coarse aggregate

Geopolymers are comparatively new generation of construction materials made from industrial by-products and supplemental cementitious materials (SCM) with high silica and alumina content. Currently, the demand for SCM has enlarged significantly based on global climate change action plans, so its use through the geopolymerisation process has attracted the attention of researchers from all over the world. This article focuses on the main mechanisms of construction and demolition (C&D) waste on the resulting physical, mechanical and durability properties of geopolymer concrete (GPC) on fresh and hardened state. This article deals with the partial substitution of coarse aggregates (CA) by C&D waste on GPC. The partial replacement of CA was carried out in five proportions, that is, 0%, 10%, 20%, 30% and 40%, and every sample was analysed to determine the slump cone, the compressive strength, flexural strength and splitting tensile strength for 7 and 28 d. It is observed that the percentage variation of C&D waste influences the hardening properties of GPC. The analysis of Finite element (FE) is taken by using FE software ANSYS.

Structural performance of hybrid fibres incorporated Re-Cycled aggregate RC slab

Concrete is a material that mainly consists of coarse aggregate and mortar. The forming of cracks is an existing problem in Reinforced Concrete (RC) slab. In this research, hybrid fibres namely steel and polypropylene fibres in suitable combinations are identified and incorporated to concrete to regulate the formation and development of cracks in RC slabs. In Hybrid Fibre Reinforced Concrete (HFRC), 1 per cent of steel fibre and 0.30 per cent of polypropylene fibre is added, which is the effective amount of reinforced concrete added based on information obtained from the various research studies. In addition, now-a-day use of re-Cycled Aggregate (RCA) is strongly recommended to address the lack of traditional coarse aggregate. By using RCA as a partial substitution of coarse aggregate with an inclusion of 1 % of steel fibre and 0.30 % of polypropylene fibre to the concrete volume in the study, a typical approach is recommended. One-way type of RC slab, 1350 mm × 500 mm × 100 mm in dimension, is cast and tested in the laboratory in compliance with the Indian standard code IS 456: 2000 [1] . The compressive strength of concrete, load carrying capacity, load versus deformation characteristics, stiffness and ductility relationship properties of the RC slabs was compared and discussed between control specimens and 0 to 50 percent of partially substituted RCA specimens.