Production Of Lightweight Concrete Research Articles

An Experimental Study of Concrete Mixed with Coconut Shell as Partial Replacement of Course Aggregate

The high cost of conventional construction materials affects the economy of structure. The possibility of utilizing recycled coconut shell aggregates in concrete as coarse aggregate is examined in the present study. An optimum percentage replacement of coarse aggregate with coconut shell aggregate is determined from the study. Coconut shell is a lightweight material thus producing lightweight concrete. The replacement of coarse aggregate of coconut shell by 10%, 20% and 30%. The Design mix used is M20 grade and testing of specimens are conducted after 7 and 28 days of curing. The flexural and compressive strength of concrete are tests. The main objective is to encourage the use of these waste products as construction materials in low-cost housing Aggregate is a major ingredient for making concrete, occupying almost 70-80% part of concrete. Conventionally crushed rocks are used as coarse aggregate and river sand as fine aggregate. Both are naturally available materials. Due to the speedy growth of construction works, conventional aggregate sources are exhaust very fast leading to a significant increase in the cost of construction. For sustainable development, these materials should be used wisely and alternative materials need to be searched to replace regular aggregate. A large number of studies have been done to search for alternative materials for the production of concrete. At the same time due to fast industrialization, production of waste material is increasing day by day. Its disposal has become a real problem. It can be concluded that the ideal amount of coconut shell replacement for coarse aggregate for M20 Concrete is 10% -20%. Key Words: Concrete Mix, Coconut shell, Low cost housing, Flexural strength, Compressive strength, Design mix, Replacement of Course Aggregate.

Mechanical Properties of Lightweight Aggregate Concrete Containing Unground Palm Oil Fuel Ash as Partial Sand Replaceme

Escalating quantity of industrial by-products generated, including oil palm shell (OPS) and palm oil fuel ash (POFA ) of the palm oil industries, has been a concern to many analysts. They are mostly disposed off as wastes that would heavily impact the environment quality. Therefore, this paper aimed to investigate the possibility of consuming these wastes by using OPS and POFA as replacement materials for fine aggregates in the concrete mixture. The mixtures were prepared by integrating unground palm oil fuel ash of 0%, 10%, and 20% (by weight of sand) to produce lightweight concrete. The experiments observed the mechanical performance of these specimens for 180 curing days. The results show the enhancement of concrete strength relative to the control mixture by using 10% of ash. This is owing to void filling mechanism and product of pozzolanic reaction due to the fine particles of the ash.

New strategy for closing the plastic loop: Lightweight concrete by the waste of recycled synthetic fibers

Environmental protection related to the mismanagement of plastic waste and rational consumption of natural raw materials is an essential goal of the building materials industry and the production of structural lightweight concrete. Plastic waste is not a degradable polymer and increases severe environmental burdens each moment due to its significant quantity. In addition, the recycling of plastic materials is lower than that of other materials. It is usually described as an inefficient and complex process. The textile industry offers an eco-green, effective part of the recycling loop of plastics. Therefore, many textile mills consider recycled plastics as synthetic fiber raw material, particularly for household applications. Unfortunately, such a process results again in another waste known as popcorn. This study aims to introduce an end-of-life management option for the waste of synthetic textile fibers manufactured from recycled plastic materials in construction. Furthermore, the study presents a novel approach to develop an eco-green lightweight structural concrete by incorporating a unique type of lightweight aggregate (popcorn aggregate) as a 100% environmentally friendly product. To achieve that, fourteen mixes of fine and coarse popcorn aggregate contents (25%, 50%, and 100%) are considered to replace the fine and coarse natural aggregate by volume. In addition, the workability, compressive, splitting tensile, flexural strength, microstructure analysis, and Energy Dispersive X-ray Spectrometry are assessed. The results revealed that the higher the substitution ratio of ordinary aggregates by popcorn aggregates, the higher the slump value. Meanwhile, the unit weight of hardened concrete exhibited a tangible decrease at a 100% replacement ratio of fine and coarse natural aggregates; a 56% reduction achieved a dry density of 1059 kg/m³. Moreover, the compressive strength results indicated a decrease of 32% for mixing 25% fine e popcorn aggregate with 100% coarse popcorn aggregate, resulting in a compressive strength of 45 MPa. Fine ally, no evidence of chemical interactions between the popcorn aggregate and the cementitious element during hydration is found.

Material Performance Evaluation of Cinder Based Light Weight Concrete with Micro-reinforcement

Objectives: The present work examines the viability of using industrial solid waste, like cinder, to create lightweight aggregate concrete. Utilizing cinder aggregate as a substitute material for coarse aggregate in producing concrete not only helps in the conservation of natural resource but also provides a feasible solution for solid waste management. Method: The mechanical characteristics of cinder based lightweight concrete were improved by the inclusion of polypropylene fibre as micro-reinforcement, in volume proportions of 0.1%, 0.2%, 0.3%, and 0.4%. The laboratory tests that were conducted on the polypropylene fibre reinforced cinder based lightweight concrete included compressive strength test on cube specimen and cylinder specimen, flexural strength test on prism specimen and modulus of elasticity test on cylinder specimen. Findings: The findings show that cinder aggregate can be satisfactorily utilized as an alternate material to coarse aggregate in the production of lightweight concrete. It has been found that 0.3% of polypropylene fibre was the ideal dosage of micro-reinforcement that can be incorporated in lightweight concrete. Novelty: Further, a multiple linear regression (MLR) model was suggested to evaluate the performance parameters of the fibre-reinforced lightweight concrete, providing an alternative to the time and material consuming experimental works. Scatter plots and Statistical indicators such as R2, RMSE and MAPE indicated that the model demonstrated a strong correlation between the predicted values and the experimental results. Keywords: Cinder aggregate, Lightweight concrete, Mechanical characteristics, Micro reinforcement, Regression model

Residue fluidized catalytic cracking in lightweight polystyrene concrete: A sustainable construction solution

This study explores the potential of Polystyrene concrete, a globally recognized lightweight concrete, in the context of Vietnam's construction industry. The research incorporates non-hazardous industrial waste, specifically Residue Fluidized Catalytic Cracking (RFCC), as a novel additive in the production of lightweight concrete. The systematic approach involves evaluating different cement types and gradually replacing cement with RFCC to identify an optimal formula for lightweight Polystyrene concrete. The study aligns with global sustainability goals and addresses local gaps by contributing practical insights and solutions to challenges in traditional brick production. The experimental setup utilizes Expanded Polystyrene (EPS) granules, standard cement types (PCB50, PCB40, and PCB30), and super foaming additives. Results indicate the feasibility of replacing up to 10% of cement with RFCC, offering a promising avenue for effective industrial waste management. This research aligns with the Sustainable Development Goals (SDGs) and contributes to a more environmentally conscious scientific community.

Flowability and Cracks Patterns of Lightweight Concrete Subjected to Compression and Tension Loading

AbstractConcrete is one of the most widely used buildings materials in construction. One of the concrete types used is foam concrete which is produced by adding liquid foam (a foam agent) to water in the concrete design mix. The purpose of the foam agent is to stabilize air bubbles during the concrete hardening process. This study aims to analyse the flowability and crack patterns of lightweight concrete subjected to compressive and tensile loadings. A lightweight concrete specimen was made using foam, fine aggregate, and Portland Composite Cement. Foam agent and water are combined in a 3:10 ratio to produce lightweight concrete. There were three different foam volume variations namely 15.7 litres, 25.12 litres, and 37.68 litres. The specimens were prepared using cylinders with dimensions of 10 cm by 20 cm. Flowability testing was carried out when lightweight concrete is still in fresh condition. Cracks in foam concrete were examined after compressive and tensile strength tests were performed at 3, 7, and 28 days of age. The research results show that the fresh lightweight concrete mixture from each mixture is sticky, which could prevent the segregation or bleeding. The crack patterns for the compressive and indirect tensile strength tests were essentially identical; namely parallel to the load direction at the age of 3, 7, and 28 days. The cracks were categorized as columnar crack patterns. It could also be noted that the concrete became more resistant as it ages, as the number of cracks decreased.

Optimization of Tuff Stones Content in Lightweight Concrete Using Artificial Neural Networks

Tuff stones are volcanic sedimentary rocks formed by the consolidation of volcanic ash. They possess unique geological properties that make them attractive for a variety of construction and architectural applications. Considerable amounts and various types of Tuff stones exist in the eastern part of Jordan. However, the use of Tuff stones often requires experimental investigations that can significantly impact the accuracy of their physical and mechanical characteristics. To ensure consistent and predictable properties in their mix design, it is essential to minimize the effects of these experimental procedures. Artificial neural networks (ANNs) have emerged as a promising tool to address such challenges, leveraging their ability to analyze complex data and optimize concrete mix design. In this research, ANNs have been used to predict the optimum content of Tuff fine aggregate to produce structural lightweight concrete with a wide range (20 to 50 MPa) of compressive strength. Three different types of Tuff aggregates, namely gray, brown, and yellow Tuff, were experimentally investigated. A set of 68 mixes was produced by varying the fine-tuff aggregate content from 0 to 50%. Concrete cubes were cast and tested for their compressive strength. These samples were then used to form the input dataset and targets for ANN. ANN was created by incorporating the recent advancements in deep learning algorithms, and then it was trained, validated using data collected from the literature, and tested. Both experimental and ANN results showed that the optimum content of the various types of used Tuff fine aggregate ranges between 20 to 25%. The results revealed that there is a clear agreement between the predicted values using ANN and the experimental ones. The use of ANNs may help to cut costs, save time, and expand the applications of Tuff aggregate in lightweight concrete production. Doi: 10.28991/CEJ-2023-09-11-013 Full Text: PDF

Shrinkage and thermo-mechanical properties of concretes incorporated with different substitutions of natural aggregates by cold bonded calcined attapulgite lightweight aggregates

Calcined attapulgite (CAT), a fibrous calcined clay represents a promising option for advancement as a relatively new cementitious material with strong pozzolanic activity. This study investigates the impact and potential use of CAT in producing cold-bonded lightweight aggregates and their utilization in microsilica (MS) and fly ash (FA) blended concretes by analyzing the shrinkage and thermo-mechanical behavior. Initially, attapulgite rocks were processed including crushing, grinding and calcination to produce pozzolanic material. Following this, a dry powder mix of 80% calcined attapulgite (CAT) and 20% Portland cement (PC) was pelletized into calcined attapulgite lightweight aggregates (CATLWAs) using cold bonding with moisture and cured for 28 days. Subsequently, twelve concrete mixtures were formulated considering different substitutions of normal aggregate with CATLWAs and various proportions of PC, MS and FA. Mechanical properties such as compressive, splitting, and flexural strengths as well as elastic moduli and impact resistance were evaluated. Drying shrinkage, weight loss and thermal conductivity were assessed for all mixtures. Likewise, scanning electron microscopy was employed to analyze microstructural changes. Experimental results indicated that the incorporation of fine and coarse CATLWAs reduced the concrete unit weight by approximately 22% compared to the control mixture. However, there was a declining trend in mechanical properties, especially for impact resistance with increasing CATLWA content. However, the use of binary and ternary blends of cementitious materials improved overall mechanical behavior. Regardless of CATLWA content, the utilization of CATLWA enhanced thermal conductivity up to 46.9%. These findings hold significance for using CATLWAs in sustainable lightweight concrete production, thus advancing lightweight concrete technology and offering valuable insights into their advantages and constraints.

Using recycled bricks to improve the compressive strength of concrete and produce lightweight concrete

This research presents the aim of using sustainable materials like crushed bricks from the demolition of old buildings as additives to preserve the environment, reduce energy consumption, reduce the cost of concrete, improve the properties of concrete, and obtain lightweight concrete for high buildings with more fluidity for narrow places. Also, it discusses the best replacement ratios because the knowledge about them is still lake. Three mixes of concrete were used and tested. Mix-1was the standard, where the replacement of coarse aggregate with crushed brick aggregate has been used in mix-2, the mix-3 was to study the replacement of fine aggregate by powder brick. In this analysis, only two factors were taken into account: the percentage of coarse aggregate replaced by brick aggregate (from 0 to 50%) and the percentage of fine aggregate replaced by brick aggregate (from 0 to 75%). Compressive strength was tested after curing at ages (7, and 28) days. The results showed that concrete with crushed brick aggregate reduces unit weight and increases of compressive strength of concrete. Using mix-2 increased the compressive strength by about 9.7%, and 7% at ages (7, 28) days respectively, and reduced the weight by 11%. Also, using mix-3 increased the compressive strength with high percentages of about 59%, and 61% at ages (7, and 28) days respectively, with a little percentage of reducing the weight by 2%.

Effect of Sawdust and Coconut Shell on the Mechanical Properties of Concrete

The increased demand for infrastructure due to global population growth has resulted in the depletion of natural aggregate sources and the escalation in the cost of building materials. There is also the problem of environmental pollution as a result of wastes generated from agricultural activities. This has led to various studies aimed at investigating the use of waste materials as substitutes for natural aggregates in concrete. In this research, sawdust (SD) And coconut shell (CS) were used as partial replacements for fine and coarse aggregates respectively in concrete. Concrete cubes, cylinders and prisms were cast and tested for compressive, split-tensile and flexural strengths at 0% (control), 10%, 20%, 30% and 40% replacement of sand and granite by weight with SD and CS respectively, after curing in water for 7, 14 and 28 days. The results showed that as SD and CS increased in the matrix, the concrete's compressive, split-tensile and flexural strengths decreased. The modified mixes can however be used as economic alternatives for lightweight concrete production as the production cost reduces with an increase in the SD and CS in the matrix. An optimum of 10% substitution by weight of fine and coarse aggregates with SD and CS respectively is recommended for concrete production.

Experimental investigation on the mechanical strength and thermal conductivity of concrete lightened by olive mill solid waste

The objective of this study is to explore the feasibility of producing lightweight concrete using olive mill solid waste as Olive Pomace Aggregates (OPA), an agricultural by-product. The use of these co-products as a substitute for natural aggregates, such as natural sand, would create additional economic, social, and environmental value while also facilitating their management and handling. To carry out this research, we took into account our previous understanding of lightweight concrete production, the characteristics of natural aggregates and their potential substitutes, and also explored the potential utilization of OPA as a sustainable building material.The study evaluates the mechanical strength and thermal conductivity of lightweight concrete made with OPA to determine if it can be used as a raw material to produce cementitious materials. The concrete mixtures studied contain OPA as a partial substitute for fine aggregates (natural sand), Ordinary Portland cement, natural gravel, natural sand, and water. The research studies various proportions of sand substitution by OPA, ranging from 0% (reference concrete) to 15% with a step of 5%. The experimental assessment focuses on determining whether the mechanical and thermal properties of the developed lightweight concrete can be improved compared to the reference concrete. The results indicate that the concrete mixture containing 5% OPA achieved the most favorable outcomes. After a maturation period of 28 days, the compressive strength reached 25 MPa, while the density decreased by 5.69% compared to the density of the reference concrete.The concrete containing 5% pf OPA achieves a thermal conductivity of 0.86 W/m.K, resulting in a reduction of approximately 34% compared to the reference concrete.This study demonstrates that using 5% of OPA can be a viable substitute for natural sand in lightweight concrete production, offering benefits in terms of both mechanical and thermal properties. Moreover, the resulting concrete mixture satisfied the minimum strength requirements for structural use as a construction material.

A novel TOPSIS linear programming model based on response surface methodology for determining optimal mixture proportions of lightweight concrete blocks containing sugarcane bagasse ash

The idea of utilizing waste from the agro-industrial sector to produce lightweight concrete is one of the good ideas for recycling and reusing waste materials. In a lightweight concrete production process, determining a material's optimal parameters is crucial, since it can help optimize the important properties of lightweight concrete blocks. This study introduces a novel TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) linear programming model, based on the Response Surface Methodology (RSM), to optimize the parameters of lightweight concrete blocks. The compressive strength, dry density, and water absorption are considered important responses, while black bagasse ash, cement with white bagasse ash, and aluminum powder are the factors considered. The proposed method successfully optimized the parameters, as confirmed by experimental results, showing a 7.22% increase in compressive strength, a 9.19% increase in dry density, and a 16.83% decrease in water absorption compared to the original condition. These improvements were achieved by using the optimal mixture ratio of 6:1:0.05 by weight, which consists of sugarcane bagasse ash, cement, and aluminum powder. The advantages of the proposed method are as follows: This paper presents a novel method called the TOPSIS linear programming model, which is a modified version of the original TOPSIS method, to calculate the closeness efficiency for each run. The proposed method is simpler and more practical, making it useful for solving multi-response optimization problems with large inputs. In addition, this research contributes to the advancement of sustainable materials and offers a practical solution for optimizing lightweight concrete block properties.

Analysis of Load and Deflection Curves on Reinforced Styro-Con Beams

Lightweight concrete technology develops along with construction needs. Styrofoam is an alternative ingredient that can be used in a mixture of concrete to produce lightweight concrete. Experimental research to see the performance of lightweight concrete with the addition of styrofoam. This study uses two types of samples, namely concrete cylinders and beams. The compressive strength and deflection tests were carried out on four types of concrete with various styrofoam mixtures. The results showed that the styro-con performed equivalent to regular concrete based on deflection and strength.

Production of Lightweight and Heat-Insulating Concrete Using Minced Tires

The main objective of the research was to study the effect of crushed rubber tires, which were used as a substitute for coarse aggregate (gravel) in production of lightweight and heat-Iinsulating concrete. The volume ratios of the mixtures used were as follows: First was 2 gravel, 1.5 sand, and 1 cement. The second was 2 minced tires, 1.5 sand, and 1 cement, while the third mixture was 1 minced tires, 1 spring gravel, 1.5 sand, and 1 cement. Concrete cubes were produced and the results were compared with ordinary concrete. The following tests were carried out: compressive, resistance, water absorption, porosity, volumetric density, specific weight, treatment with alkaline solutions -KOH NaOH, and thermal conductivity. The results of the tests proved that the addition of minced tires negatively affected the compressive strength compared to the reference concrete at the ages of 7, 14, and 28 days. As an alternative to Al-Naba gravel, it was also shown that there was an increase in water absorption with an increase in the proportion of minced tires relative to the water absorption in the reference mixture. Also, the density values of lightweight concrete decreased compared to the regular reference concrete, which leads to a reduction in the weight of the dead loads and therefore the foundations and their quality. Because of the high temperatures in the summer as these types of concrete do not react with alkaline solutions such as NaoH and KOH, and this is one of the advantages for concrete work.

Çimento Hamuruyla Kaplanmış Pomza Agregalarının Su Emme ve Darbe Dayanımı Performanslarının İncelenmesi

Pumice aggregate, which has high reserves in our country, is used in the production of lightweight concrete, however, it is not preferred as a structural lightweight concrete since its low mechanical properties. The mechanical properties of pumice aggregates can be improved by coating their surfaces. In this way, the coated pumice aggregates can be used to produce lightweight concrete. This study investigated the coating potential of Kayseri and Ahlat pumice aggregates with cement paste. The flow diameter, marsh funnel, and 28-day flexural and compressive strength values of the cement paste 0.55-0.50 w/b ratio and 0.35-0.30 w/b ratio with 1.5% plasticizer admixture were determined. At the end of 28-day curing, the Coating effectiveness of the produced samples was investigated via optical microscope, aggregate impact value, water absorption, and unit weights, and comparisons were made with uncoated aggregates. After coating, it was determined that Ahlat and Kayseri pumice aggregates were crushed by 11% and 18%, considering the impact strength result, moreover a decrease in water absorption was obtained by 50.49% and 78.32%, respectively. As a result, the water absorption values of the coated pumice aggregates decreased, and the aggregate impact values increased compared to the uncoated pumice aggregates.

Production of autoclaved lightweight concretes using pottery stone and bagasse ash

This study investigated the influence of pottery stone and bagasse ash on the mechanical features of autoclaved lightweight concrete. Pottery stone is a natural resource of igneous rock weathering commonly exists with white clay, feldspar and limestone. This raw material is mainly composed of quartz and mica that has been used for the production of ceramic products. Bagasse ash is a waste product of the sugar refining process that causes serious environmental pollution. Pottery stone and bagasse ash waste were physically characterized and partially substituted by the weight of cement in lightweight concrete with the addition of aluminium powder at a certain amount. The use of aluminium powder showed a positive effect on the porosity of lightweight bodies. Compressive strength, density and thermal conductivity were determined. Pottery stone can be used as a natural pozzolan for the production of lightweight concrete. Lightweight concrete manufactured with 17.5% pottery stone and 17.5% bagasse ash showed low density and good compressive strength. Autoclaved lightweight concrete is considered an economy in the consumption of pottery stone and bagasse ash waste as cement replacement, therefore enhancing the possibility of its reuse in a sustainable way.

The Use of Recycled Tire Rubber, Crushed Glass, and Crushed Clay Brick in Lightweight Concrete Production: A Review

Worldwide, vast amounts of waste are produced every year and most waste is sent directly to landfills or burnt, which has severe and harmful impacts on the environment. Recycling waste materials is considered the most visible solution to protect the environment. Using scraps in concrete production is a proper method for getting rid of wastes, improving the characteristics of concrete, reducing the consumption of natural aggregates, and can be used as cementitious materials that decrease cement production so that the CO2 that is produced during cement manufacturing decreases. This review paper summarizes the use of recycled waste materials, including rubber tires, crushed glass, and crushed clay brick in concrete, as a fractional replacement of aggregates, cement, etc., to develop eco-friendly lightweight construction materials. It has been concluded that the dry density of sustainable concrete decreased to 4, 21.7, and 31.7% when crushed glass, clay brick, and rubber tire were incorporated into the concrete instead of traditional aggregate, respectively. Waste rubber has good results in sulfate, thermal, and impact resistance, while glass powder and finely crushed clay brick helped to improve mechanical properties by increasing reach by 33% for glass and a slight increase for crushed clay brick, as well as thermal resistance compared to normal concrete. Moreover, due to the low particle density of these waste materials compared to that of normal-weight aggregates, these materials can be utilized efficiently to produce lightweight concrete for structural and non-structural applications such as road engineering, flooring for mounting machinery, highway and rail crash barriers, permeable pavement, interlocking bricks, insulation, filling concrete, and bearing walls.

Potential of Waste Material as Coarse Aggregates for Lightweight Concrete Production: A Sustainable Approach

In recent times, there has been growing interest in utilizing waste materials as coarse lightweight aggregates in the production of lightweight aggregate concrete. This approach has been gaining momentum as it has the potential to address the environmental concerns that come with conventional construction practices. The objective of this review paper is to evaluate the viability and potential of waste materials as coarse lightweight aggregates for producing lightweight aggregate concrete. This paper reviews the current research on various types of waste materials, including waste plastic, recycled concrete aggregate, slag, fly ash, and expanded polystyrene, as potential candidates for coarse lightweight aggregates. The paper highlights the properties and characteristics of these waste materials and their suitability for use as coarse lightweight aggregates. Additionally, the evaluation explores the mechanical characteristics of lightweight aggregate concrete that is generated using waste materials as coarse lightweight aggregates. Specifically, it compares the compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity of lightweight aggregate concrete that includes waste materials with those of typical concrete. Furthermore, the paper discusses the sustainability benefits of using waste materials as coarse lightweight aggregates. By using waste materials in construction, not only are resources conserved, but waste is also diverted from landfills, reducing the negative impact on the environment. In conclusion, this review paper demonstrates that the use of waste material as coarse lightweight aggregate for lightweight aggregate concrete production is a viable and sustainable approach. The application of waste materials as coarse lightweight aggregates in lightweight aggregate concrete demonstrates mechanical characteristics that are similar to traditional concrete. Moreover, utilizing waste materials in this manner provides environmental advantages. This study offers valuable insights into the implementation of waste materials in construction, and it emphasizes the possibility of further exploration and advancement in this domain. For this review, a total of 15 articles were analyzed, with publication dates ranging from 2005 to 2021. The study contributes to several Sustainable Development Goals (SDG 9/11/12/13) set by the United Nations such as providing insights into the role of industry, innovation, infrastructure, sustainable cities, responsible consumption, production practices, and climate action.

Comparative Study of the Lightening of Concrete Through the Use of Recycled Tire Rubber and Expanded Clay Aggregate

Abstract The waste of tire rubber is characterized by the generation of huge amounts, which is annually discarded. This waste causes problems for human health and the environment. Thus, the valorization of recycled tire rubber in concrete production is considered as an alternative and sustainable solution. This experimental work is a comparative study, which aims to investigate the possibility of using recycled tire rubber as a fine aggregate in the production of lightweight concrete. To achieve this objective, two types of lightweight concrete containing (35, 70 and 100%) of expanded clay and (5, 10 and 15%) of recycled tire rubber as a fine aggregate were produced. Their fresh properties were investigated using slump, density and air content tests, while the hardened properties were investigated by compressive strength, flexural strength, ultrasonic pulse velocity, and water absorption tests. The results obtained showed that the utilization of both expanded clay aggregate and recycled tire rubber leads to a reduction in density and mechanical strength but increases the porosity of lightweight concrete. However, the lightweight concrete containing the expanded clay aggregate had a higher efficiency factor than those containing recycled tire rubber.

Performance of resource saving agro-industrial wastes and their utilization in lightweight concrete -A review

The high demand for natural aggregates has created opportunities for the use of agro-industrial waste in the building sector brought on by rising urbanization and the disposal issue of agricultural and industrial waste. Numerous agricultural waste and industrial by-products are already employed in concrete in place of cement, fine aggregate, coarse aggregate and reinforcing elements. Furthermore, there is an increase in the use of Lightweight concrete (LWC) in civil structures such as high-rise buildings, off-shore structures, and long-span bridges owing to the need of concrete, lighter than the conventional one. Presence of natural aggregates makes the concrete dense and heavy, hence the use of lightweight aggregates (LWA), such as perlite, paper industry waste, expanded shale, volcanic pumice, slate, wood ash waste, and expanded polystyrene (EPS), in the production of LWC can effectively decrease the self-weight of a structure. In a comparable manner agricultural wastes, like oil palm shell (OPS), coconut shell (CS), rice husk ash (RHA) and industrial waste like fly ash, plastic aggregate, silica fume (SF), metakaolin (MK) have the potential of a LWA. This study reviewed the utilization of oil palm shells (OPS), coconut shells (CS), expanded polystyrene (EPS), and silica fume (SF) in concrete, among the numerous available agro-industrial wastes. For the past decade, research has been ongoing on aggregate processing to meet special concrete requirements such as low density, thermal insulation, and strength. These wastes exhibit similar properties to conventional concrete when used in combination with mineral additives like SF and RHA, among others. The study also highlights the eco-efficiency and functional benefits of using these wastes as lightweight aggregates (LWA).