Performance Of Lightweight Concrete Research Articles

Experimental Investigation of Mechanical Properties of Concrete Mix with Lightweight Expanded Polystyrene and Steel Fibers

The demand for lightweight aggregates in concrete compositions for diverse structural and non-structural applications in contemporary building construction has increased. This is to achieve a controllable low-density lightweight concrete, which reduces the overall structural weight. However, the challenge lies in achieving an appropriate strength in lightweight concrete while maintaining a lower unit weight. This research aims to evaluate the performance of lightweight concrete by integrating expanded polystyrene (EPS) as a partial replacement for coarse aggregate. Test specimens were cast by blending EPS with coarse aggregate at varying proportions of 0%, 15%, 30%, and 45%, while maintaining a constant water-to-binder ratio of 0.60. To enhance the bonding and structural capabilities of the proposed lightweight concrete mixes, reinforcement with 2% and 4% steel fibers by volume of the total concrete mix was incorporated. Silica fume was introduced into the mix to counteract the water hydrophobicity of EPS material and enhance the durability of lightweight concrete, added at a rate of 10% by weight of cement in all specimens. A total of 60 samples, including cylinders and beams, were prepared and cured over 28 days. The physical and mechanical properties of the lightweight EPS-based concrete were systematically examined through experimental testing and compared against a standard concrete mix. The analysis of the results indicates that EPS-based concrete exhibits a controllable low density. It also reveals that incorporating reinforcement materials, such as steel fibers, enhances the overall strength of lightweight concrete.

Fracture behavior of ultra‐high performance lightweight concrete: In situ investigations using μ‐CT

AbstractIn various research projects at the University of Kassel, the concept of lightweight concrete has been combined with that of ultra‐high performance concrete (UHPC). Due to the high performance of the UHPC matrix, lightweight concretes (UHPLC) with strengths of 60‐130 MPa and bulk density of 1.5‐1.9 kg/m3 were developed. This material can be used in many applications because of its low thermal conductivity, low weight and thus easy to transport, recyclable and can be prefabricated. Thus, it meets today's multifunctional requirements for building materials. The brittle material failure of UHPC without fibers is not observed with UHPLC. Instead, the concretes fail in hourglass shape under compressive stress, as seen in standard concretes. This constellation is not only responsible for the reduction of strength and Y‐modulus, but also predicts a ductile failure. For a better interpretation of the fracture behavior and fracture pattern, images of the UHPLC were taken in a highresolution computed tomography (μ‐CT) scanner. Between images, the sample was loaded and the load was kept constant during the measurement. The data was evaluated on the basis of a damage parameter, as well as crack openings during stable crack growth and the crack pattern after the maximum load was exceeded.

Synergistic Effect of Combined Polymorphs Anatase-Rutile Nano-Modified Lightweight Concrete on Photocatalytic Reduction of NOx, Self-Cleaning Performance, and Antimicrobial Properties

Anatase, one of the polymorphs of titanium dioxide (TiO2), has become the most widely used semiconductor for photocatalytic materials due to its chemical and physical properties. However, researchers have been studying the use of alternative materials (e.g., ZnO, N-doped, and C-doped TiO2) to improve the photocatalytic activity of cementitious materials. In this paper, we propose a modification of lightweight concrete by introducing mixed phases of titanium dioxide—anatase and rutile—to enhance its photocatalytic performance. The efficiency of NOx degradation of nano TiO2-modified concrete, its self-cleaning performance, and its antimicrobial properties were studied. The photocatalytic activity of lightweight concrete without TiO2 and concrete with the addition of anatase, rutile, and anatase-rutile was compared. The results show that modifying the samples by adding a mixture of anatase and rutile (2.5 wt % A + 2.5 wt % R) significantly improved the photocatalytic performance of lightweight concrete.

Rosaceae Nut-Shells as Sustainable Aggregate for Potential Use in Non-Structural Lightweight Concrete

Apricot (AS), peach (PS), and plum shells (PlS) were examined as sustainable aggregates for non-structural lightweight concrete. The extraction of natural resources has a significant environmental impact and is not in line with the Sustainable Development Goals (SDGs) of Agenda 2030. Recycling agri-food waste, such as fruit shells, fully respects circular economy principles and SDGs. The chemical and physical properties of the shells were investigated using scanning electron microscopy (SEM) for microstructure analysis and TG-MS-EGA for thermal stress behavior. Two binding mixtures were used to prepare the concrete samples, one containing lime only (mixture “a”) and one containing both lime and cement (mixture “b”). Lime is a more sustainable building material but it compromises mechanical strength and durability. The performance of lightweight concrete was determined based on the type of aggregate used. PS had a high-water absorption capacity due to numerous micropores, resulting in lower density (1000–1200 kg/m3), compressive strength (1–4 MPa), and thermal conductivity (0.15–0.20 W/mK) of PS concrete. AS concrete showed the opposite trend (1120–1260 kg/m3; 2.8–7.0 MPa; 0.2–0.4 W/mK) due to AS microporosity-free and denser structure. PlS has intermediate characteristics in terms of porosity, density, and water absorption, resulting in concrete with intermediate characteristics (1050–1240 kg/m3; 1.9–5.2 MPa; 0.15–0.3 W/mK).

Design of lightweight concrete with olive biomass bottom ash for use in buildings

The ash generated during the combustion of biomass in electricity generation plants is a waste that has increased considerably in recent years, and whose management constitutes an environmental problem. In this regard, the recovery of biomass bottom ash as a partial replacement of natural materials for use in different civil engineering applications, as well as for the manufacture of construction materials, has been the subject of numerous studies that have shown its technical feasibility. However, for its application in the development of new sustainable materials, with thermal insulation properties, it is necessary to expand our existing knowledge of it. In this study, the use of bottom ash from original and processed biomass bottom ash in the manufacture of lightweight concrete, as a replacement for sand (15%–25%) and expanded clay (25%–35%), has been evaluated. In addition, after subjecting the ash to a grinding process, it was also incorporated into the concrete by replacing cement. The physical, mechanical, thermal and durability properties were evaluated according to regulations and the results showed that the thermal treatment applied to biomass bottom ash improved the mechanical performance of lightweight concrete. Likewise, thermal conductivity was reduced by up to 43%, which allows these concretes to be used as insulating materials in buildings. Therefore, this study shows the possibility of recovering biomass bottom ash in the manufacture of lightweight concrete for use in construction.

Performance-based experimental study into quality zones of lightweight concrete using pumice aggregates

The quality and performance of concrete depends on the material used. Lightweight concrete is usually formed from aggregates with lightweight specific gravity, such as pumice. This study aims to identify the zone of quality and performance of concrete when partially replacing coarse aggregate (NA) with pumice coarse aggregate (PA). The performance parameters studied include unit weight, compressive strength, elastic modulus, tensile strength, and rupture modulus. Geochemical analysis and porosity of aggregate were carried out using SEM and X-RD. The percentage variation of pumice aggregate is 0 %PA, 25 %PA, 50 %PA, 75 %PA, and 100 %PA. Quality zones based on observations of the behaviour and mechanical properties of concrete are determined. The results show that concrete using PA consists of two quality zones, namely the brittle zone for concrete with PA above 50 % and the ductile zone for concrete with PA below 50%. Formulas to calculate the elastic modulus and the rupture modulus are proposed. Utilisation of pumice as lightweight concrete aggregate to get better lightweight concrete performance must be selective.

Comparative analysis and performance of light weight concrete with varying water cement ratio using plain and blended cement

Rapid infrastructure growth and industrialization have aided in driving growth, creating job opportunities, and reducing poverty; however, there are some challenges, such as meeting infrastructure needs, large extraction of natural aggregates required to make concrete, and disposal of waste generated by industrialization. Therefore, to promote resilient infrastructure and sustainable industrialization, the present study develops light weight concrete (LWC) from sintered fly ash aggregate (SFA) using plain and blended cement at various water-cement ratios. In the current investigation, binders such as ordinary Portland cement (OPC), Portland Pozzolana Cement (PPC), and Micro fibre cement (MF) were selected to produce LWC at water-cement ratios of 0.40, 0.44, and 0.48. The results show that LWC from OPC gives better results after 28 days, and as the curing days increase, the strength of LWC made from MF and PPC reaches closer to OPC values. LWC made from MF is the least permeable compared to OPC and PPC. Microstructure investigation reveals no distinct interfacial transition zone (ITZ) in LWC, as cement paste seals most of the pores of SFA and creates strong bonds. The findings will aid in the development of LWC with the appropriate binder for specific infrastructure project requirements.

Experimental studies on light weight concrete using LECA material

The past researches has brought down the various construction challenges such as robust design, practical difficulties, availability of materials and huge cost etc. looks for the possible solution. In the meanwhile, light weight concrete has several potential advantages like reduction of dead load, thermal and acoustic insulation. Consequently the above said challenges will be more suitably addressed in to the light weight concrete which is produced from the various light weight aggregates. Hence, an attempt is made to investigate the performance of light weight concrete using LECA material as a partial replacement for conventional aggregates in the replacement levels of 0%, 5%, 10%, 15%, 20% and 30%. For the casted specimens, mechanical (compressive strength, flexural strength and split tensile strength) and water absorption tests were conducted. In the study, 10% of the LECA material replacement is found to be the optimal percentage in all aspects.

Flexural behaviour of lightweight aggregate concrete columns

The flexural performance of lightweight concrete (LWC) columns was evaluated and limitations of ACI 318-19 in predicting the flexural crack (Mcr) and maximum (Mn) moments, as well as the minimum amount of transverse reinforcing bar (Ash(ACI)), were examined. Six LWC columns with different amounts of transverse reinforcing bar (Ash), compressive strengths of concrete (fc′) and concrete types were prepared and tested under constant axial and cyclic lateral loads. The test results show that ACI 318-19 agrees well with the Mcrof tested columns, considering the lower tensile stress of LWC columns by introducing modification factors (λ) (all-lightweight concrete, λ = 0.75; sand–lightweight concrete, λ = 0.85) for the fracture modulus of concrete (fr). In addition, ACI 318-19 underestimates Mn, irrespective of Ash, fc′ and concrete type. The ductility of LWC columns increased with the increase in volumetric transverse reinforcing bar index (ωvh). The increasing rate was lower than that of normal-weight concrete (NWC) columns. The displacement ductility ratio (μΔ), work damage indicator (W80) and equivalent damping coefficient (ξ80) of a column with 1.0Ash(ACI)were, on average, 30, 36 and 18% lower in LWC than NWC columns. Consequently, double the Ash(ACI)was required to retain a flexural ductility equivalent to that of a NWC specimen.

Effect of fly ash and bagasse ash on the mechanical properties of light weight concrete

Light weight concrete is an important part in the concrete technology. The use of mineral additives in light-weight concrete, to replace fine aggregate with fly ash and bagasse ash, helps to reduce the cement content. The present investigation aims to meet the performance of light weight concrete, by adding fly ash and bagasse ash, as fine aggregate replacement additives. The strength properties such as cube compressive strength, cylinder compressive strength and split tensile strength were investigated after different ages, to find the optimum addition of mineral additives such as fly ash and bagasse ash, in concrete. The strengths were compared and the optimal replacement level of cement with fly ash and bagasse ash was found. The cylinder compressive strength and split tensile strength of light weight concrete were measured, at the same replacement levels of mineral additives, at the age of 28 days curing. The mathematical equations were proposed to achieve cube compressive and tensile strengths, cylinder compressive and tensile strength and cube compressive and cylinder compressive strengths, concerning typical strength.

Performance of manufactured aggregate in the production of sustainable lightweight concrete

This study examines the performance of lightweight concrete incorporating manufactured lightweight aggregates with industrial by-products. The physical and mechanical properties of cold-bonded aggregates manufactured through pelletization technique with 80% fly ash, 10% cement, and 10% metakaolin with the addition of 0.2% alkali-resistant glass fibers. The manufactured aggregates have been tested with different properties like production efficiency, bulk density, specific gravity, water absorption, and impact strength thereby compared with natural aggregate results. Further, the study on properties of lightweight concrete produced with the replacement of ordinary portland cement (OPC) by ground granulated blast furnace slag (GGBFS) at different percentages varies from 0% to 50%. The lightweight concrete performance was assessed based on the slump cone test, density, compressive strength, split tensile strength, and water absorption at different curing ages. It was noticed from the results that the optimum performance of lightweight concrete was attained at 40% replacement with GGBFS. It is observed from the results that the replacement of natural aggregate by manufactured aggregates and cement by GGBFS achieved desired strength to be used as a structural material. Usage of industrial by-products in aggregates and concrete production results in both economic and environmental benefits.

The Performance of Lightweight Concrete with Recycled Polyethylene Terephthalate and Polypropylene as Demising Wall

Abstract The use of concrete has always been an important construction material used throughout the construction industry in the world. The objective of this study is to explore the potential of using lightweight concrete block mixing with plastic waste and additional plastic material as a sustainable construction material for constructing the demising wall in the current construction industry. The research is conducted quantitatively through experiments to test the density and strength of the materials. A series of experiments are conducted based on two types of plastics which are Polyethylene Terephthalate (PET) as replacement of coarse aggregate and Polypropylene (PP) fibres which corresponds to the percentage of cement mass added into the concrete mix and each with a different percentage to observe the variations throughout a series of tests. The findings show that concrete mixing with 0.5 % of Polypropylene (PP) fibres showed outstanding results in the compressive strength compared to the control specimen and PET specimen. However, if comparing the amount of recycled waste incorporated into the same size of lightweight concrete block, the PET has a higher recycling rate which is 27 times the amount of PP fibres. From the findings, the research will contribute to a wider range of sustainable building materials choices for the designer or architect in the project.

Influence of Fibres on Mechanical Properties and Fire Performance of Lightweight Concrete Incorporating with Cenospheres and Expanded Clay Aggregates

Influence of Fibres on Mechanical Properties and Fire Performance of Lightweight Concrete Incorporating with Cenospheres and Expanded Clay Aggregates

Performance of Light Weight Concrete with Coconut Shell and Fly Ash

Abstract: The major factor that affects the housing delivery is high cost of materials for any conventional concrete. This has lead to find an alternative. An attempt has been made to find an alternative by using partial replacement of coarse aggregate by coconut shell aggregate and cement by fly ash. This report provides the information obtained from a literature search. And also provides laboratory experiments on Cement, Sand, Coarse aggregate and Coconut shell. This project is done using partial replacement of coarse aggregate by coconut shell aggregate and cement by fly ash.10 % of fly ash was kept constant as replacement for cement. And Coarse aggregate was replaced by 5%, 10%, 15%, and 20% of coconut shell aggregate.30 concrete cubes of 150x150x150 mm size were casted and 3 cubes were tested after 7 days of curing and 3 cubes were tested after 28 days of curing for each percentage.30 concrete Cylinders of 150x300 mm size were casted and 3 Cylinders were tested after 7 days of curing and 3 Cylinders were tested after 28 days of curing for each percentage.15 concrete Beams of 100X100X500 mm size were casted and 3 beams were tested after 28 days of curing for each percentage. Two models were done using ANSYS Software using the same failure loads from the experimental part. Keywords: Light weight concrete, coconut shell, Fly-ash, experimental.

Acoustic performance of social housings in Brazil: Assessment of lightweight expanded polystyrene concrete as resilient subfloor

The vast majority of multi-story buildings in Brazil are not designed with acoustic treatment for impact sound insulation due to the high cost of floating floors, applied only in housings for medium and high-income populations and neglected for social housings. The use of EPS in lightweight concrete to insulate impact sound could become an extremely viable alternative in technical, economic and environmental terms. However, few studies have investigated the properties of lightweight concretes as acoustic insulators and none has investigated the lightweight concrete performance under mechanical stresses in the construction and use phases of buildings. The research aimed to investigate the equilibrium between mechanical resistance and acoustic insulation for lightweight concrete with different contents both in the laboratory and in the field. In the laboratory tests, a lightweight concrete with incorporation of 50% of EPS and density of 1100 kg/m3 achieved this optimum equilibrium, especially at frequencies above 500 Hz. In the real building, the EPS lightweight concrete with density of 1100 kg/m3 reached only L'nT,w of 74 dB, but this value is still within the minimum performance level according to Brazilian standard. The system showed no reductions in sound pressure levels at medium and high frequencies mainly because it was adhered to reinforced concrete slab, increasing sound transmission at high frequencies by reducing sound insulation of the mass-spring-mass system provided by the EPS lightweight concrete. The research results were promising, giving viability signs of applying EPS lightweight concrete subfloors in social housing in Brazil at a low production cost.

Effect of FRP thickness on axial compressive behavior of Glass Fiber Reinforced Polymer–confined lightweight concrete cylinders

It is well known that FRP can improve the performance of concrete. However, the effectiveness of FRP to enhance the performance of lightweight concrete is less explored. This study aims to investigate the effect of FRP thickness on the axial compressive behavior of GFRP-confined lightweight concrete cylinders. Nine lightweight concrete specimens wrapped with 0, 1, 2, and 3 sheets of GFRP were manufactured and tested until failure. The test confirms that the thicker specimens experienced higher axial stress and strain compared to the thinner ones.

Performance of Lightweight Concrete with Expansive and Air-Entraining Admixtures in CFST Columns

AbstractAdequate load transfer in concrete-filled steel tubes (CFSTs) requires a close interaction between the steel walls and the concrete core. The present work analyzes the adhesion and confinem...

Predicting Performance of Lightweight Concrete with Granulated Expanded Glass and Ash Aggregate by Means of Using Artificial Neural Networks.

Lightweight concrete (LWC) is a group of cement composites of the defined physical, mechanical, and chemical performance. The methods of designing the composition of LWC with the assumed density and compressive strength are used most commonly. The purpose of using LWC is the reduction of the structure’s weight, as well as the reduction of thermal conductivity index. The highest possible strength, durability and low thermal conductivity of construction materials are important factors and reasons for this field’s development, which lies largely in modification of materials’ composition. Higher requirements for construction materials are related to activities aiming at environment protection. The purpose of the restrictions is the reduction of energy consumption and, as a result, the reduction of CO2 emission. To limit the scope of time-consuming and often high-cost laboratory works necessary to calibrate models used in the test methods, it is possible to apply Artificial Neural Networks (ANN) to predict any of the concrete properties. The aim of this study is to demonstrate the applicability of this tool for solving the problems, related to establishing the relation between the choice of type and quantity of lightweight aggregates and the porosity, bulk density and compressive strength of LWC. For the tests porous lightweight Granulated Expanded Glass Aggregate (GEGA) and Granulated Ash Aggregate (GAA) have been used.

Experimental research on the performance of lightweight concrete containing foam and expanded clay aggregate

This work addresses the preparation of self-flowing lightweight aggregate foamed concrete (LAFC) resulting from the mixing of stable foam, expanded clay aggregate (ECA) and silica fume (SF) as main raw materials. Formulated LAFC mixtures were tested for the mechanical, thermal, sorption and high-temperature resistance properties. Results showed that the increase in the volume of foam from 0% to 20% considerably improved the flowability of LAFC and LAFC mixtures were categorized into high stable visual stability index. Compressive strength of LAFC mixtures was reduced from 24.75 MPa to 21.10, 15.95 and 12.05 MPa respectively when foam volume was increased from 0% to 10, 15 and 20%. Thermal conductivity of LAFC mixtures was 0.84, 0.77, 0.65 and 0.53 Wm−1K−1 for the 0, 10, 15 and 20% foam volume respectively. The addition of SF enhanced the strength and thermal conductivity of LAFC mixtures. Sorption coefficient and porosity of LAFC were gradually increased from 0.22 to 0.85 kgm−2min−0.5 and 25.68–39.74% by increasing the volume of foam from 0% to 20%. However, incorporation of SF reduced the sorptivity and porosity of LAFC. Effect of high temperature was more prominent on the compressive strength of LAFC as compared to the density of LAFC.

Mechanical properties of concrete with substitution of coated styrofoam balls on coarse aggregate

Substitution of Styrofoam balls on coarse aggregates reduced concrete self-weight. Coating on Styrofoam ball surface makes ball has shell on its surface and could increase the adhesive strength between ball surfaces and cement paste. The coating materials made by mixing of Portland cement and RCC-15 (Residual Catalytic Cracker-15) as pozzolanic material. 20 mm diameter Styrofoam balls are used. Coarse aggregates substituted by 5%, 15%, and 20% Styrofoam balls. The test specimens used three 10x20cm cylinders for each variant. Beam specimens of 15x15x60cm used for bending strength test by third point loading method. The testing of mechanical properties were 7, 14, and 28 days compressive strengths, 28 days split-tensile strengths and 28 days flexural strengths. The experimental results of concrete with various Styrofoam ball substitutions of 5%, 15%, and 20% at 28 days show the average compressive strengths are 27.6 MPa, 24.3 MPa, and 20.3 MPa, the splittensile strengths are 2.5 MPa, 2.2 MPa, and 1.7 MPa, and the flexural strengths are 5 MPa, 4.5 MPa, and 3.8 MPa, respectively. The compression strength could be predicted by density ratio method and air content method. The experimental results show that all of the variants of Styrofoam ball coarse aggregates concrete are adequate to achieve structural strength, and have nearly compressive strengths compared with the prediction by density ratio method and air content method. Styrofoam balls substitution content could be increased to make the concrete density below 1,900 kg/m3 and compressive strength above 17.5 MPa to reach structural lightweight concrete performance.