Compressive Strength Of Lightweight Concrete Research Articles

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.

Prediction of optimum compressive strength of light-weight concrete containing Nigerian palm kernel shells

Palm kernel shells (PKS) are vast agricultural by-products that possess silica and alumina minerals in Nigeria. The use of PKS as aggregates has not been standardized for public use, hence, there is need for the prediction and optimization through trial mixes. A target mix was calculated based on American Concrete Institute, ACI code using PKS laboratory properties. Subsequently, factorial design was used to refine mix proportions with additional fourteen mix designs through the means of central composite design. This study employed response surface methodology to design constituent mix proportions and afterward predicted respective values of their compressive strength. The effect of each mix proportion was investigated for fresh and hardened properties of light-weight palm kernel shell concrete (LWPKSC). In addition, the optimal compressive strength of concrete was predicted at 22.24 MPa and realized experimentally at 21.10 MPa. The mix proportion ratio was found to be 1:3.33:1:27 at water-cement ratio of 0.50 with an oven-dry density less than 2000 kg/m3. Finally, analysis of variance, (ANOVA) of the results showed that optimum compressive strength of the concrete could be predicted and reliable.

Optimization of cellular lightweight concrete using silica sand of sandblasting waste based on factorial experimental design

Sandblasting is a surface treatment that serves to clean the surface, improves adhesion strength and bonding performance, which in the process produces silica sand waste. Silica sand of sandblasting waste can be used as a lightweight concrete type of Cellular Lightweight Concrete (CLC). The experimental design was used factorial to find out factors influencing the compressive strength of lightweight concrete and to find the optimum composition of lightweight concrete with maximum compressive strength. The results showed that Portland cement composition and the ratio of foam significantly influenced the compressive strength of lightweight concrete with silica sand waste of sandblasting as aggregate. The optimum compressive strength of 86.13 kg/cm2 was found in the composition of Portland cement by 40%, silica sand 40% and volume ratio foam to mortar 0.6.

PENGARUH BAHAN TAMBAHAN TEXAPON TERHADAP KUAT TEKAN BETON RINGAN

Pembangunan dalam bidang konstruksi yang sangat pesat, diantaranya dalam pembangunan perumahan ,kantor rumah sakit dan sebagainya . Beton sebagai bahan bangunan sudah lama digunakan dan diterapkan secara luas oleh masyarakat sebab memiliki keunggulan – keunggulan dibanding material struktur lainya yakni memiliki kekuatan yang baik, tahan api, tahan terhadap perubahan cuaca, serta relatif mudah dalam pengerjaan.Penelituan ini dilakukan untuk mengetahui pengaruh subtitusi dengan bahan tambahan Texafon terhadap kuat tekan beton Metode yang di gunakan pada penelitian ini yakni dengan membuat beton ringan subtitusi bahan tambahan texafon sebesar 0%, 10 % dan 30 % dari berat pasir Beton ringan yang sudah di curing selama 7 hari kemudian di uji untuk mendapatkan nilai kuat tekan dari beton ringan. Hasil penelitian menunjukkan nilai kuat tekan subtitusi 0% pada umur 7 hari adalah sebesar 6,2 Mpa, Sedangkan dengan tambahan 10% adalah sebesar 5,21 Mpa dan dengan tambahan 30% adalah sebesar 4,51 Mpa.

Utilization of clinker (industrial waste) as a coarse aggregate substitution on the lightweight concrete

The Concrete starts to use material substitution to reducing its brittle character. The Material substitution is a substance that can change concrete which are coarse aggregate, fine aggregate, and cement with others materials, such as the Portland cement combine the steel slag, broken stone (coarse aggregate) with a pumice stone, etc. One of function from concrete material substitution method can exercise an industrial waste. The industrial waste can be an output of residue production from industrial activities, one of which is clinker (the waste of burning coals). The purpose of research is 1) Measure of the concrete compressive strength value between Destructive Test and Non-Destructive Test method on lightweight concrete with clinker as coarse aggregate replacements; 2) analyze the correlation of time variation on increased value of compressive strength of lightweight concrete which is tested by UTM, the hammer test, and UPV; 3) the lightweight concrete design with clinker on optimum strength for structural functions and building construction. The result of this research is to know precisely the compressive strength of lightweight concrete made from Clinker which has been tested by UTM, Hammer Test, and UPV. It provides an evaluation of the structures and building construction feasibility towards existing building as an effort to create buildings that are responsive and resistant to natural disasters.

Uji Mekanik Bata Ringan Berbahan Dasar Limbah Pengolahan Emas dengan Variasi Limbah Batu-bara dan Semen

[Title: The Mechanical Test of Lightweight Brick Made from Gold Processing Waste with Variations in Coal and Cement Waste]. The purposes of this research are to make lightweight concrete using waste processing of gold with variation fly ash and cement the better than conventional concrete. The value of this research has tested mechanics which comprises density, porosity and strength. The research has done with some stage are: 1) Make lightweight concrete using LPE with variation fly ash and cement. 2) Characterization of the samples which comprise density, porosity and the strength, 3) Analysis of tested mechanical lightweight concrete. The value of lightweight concrete to make with variation composition fly ash and cement in a series are: (0/100), (5/95), (10/90), (15/85), (20/80) who are in volume. To make lightweight concrete with composition foam and water controlled as much as 10 ml and 150 ml at all of the sample. So we get the density value of lightweight concrete without fly ash is 1.61. In lightweight concrete with fly ash, we get the minimum density of lightweight is 1.15. The porosity value of lightweight concrete without fly ash is 13.6%, and the porosity value of lightweight concrete with fly ash is 8.0%. The compressive strength of lightweight concrete without fly ash is 1.629 MPa and the compressive strength of lightweight concrete with fly ash is 1.772 MPa. The value shown to process waste processing of gold with variation fly ash and cement to be lightweight concrete can get mechanical in character of lightweight to be better than conventional concrete.

Combined Effects of Bottom Ash and Expanded Polystyrene on Light-weight Concrete Properties

The benefits of using waste materials as a partial replacement for cement in high performance concrete are also discussed. This paper presents the combined effects of bottom ash TPP “Vung Ang” and expanded polystyrene aggregate on different the properties of light-weight concrete. Twenty different concrete mixtures with a water to cement ratio of 0.4 and superplasticizer to cement ratio of 0.015 were used. On the one hand, the EPS was partially replaced with (0 ÷ 40)% by volume of concrete mixture. On the other hand, the fine aggregate was replaced with (0 ÷ 30)% by mass of BA TPP “Vung Ang”. The engineering properties, including workability, density and compressive strength of light-weight concrete were investigated at different curing times. The level of decrease in the strength depends upon the replacement level of EPS and BA. Specifically, the concrete containing 40% EPS and 30% BA at 28 days of age decrease in average density and strength were 43.2% and 26.4%, respectively, in comparison with the control concrete.

Effect of matrix particle size on EPS lightweight concrete properties

Expanded polystyrene lightweight concrete is a composite which can be made by adding expanded polystyrene aggregate in normalweight concrete (as matrix). The research was focused on the effect of properties and volume of the matrix on the properties of lightweight concrete. The results show that properties of structural polystyrene concrete, such as workability and compressive strength, depend on the aggregate size of the matrix. It also shows that decreasing aggregate size of the matrix is the effective way to increase workability and compressive strength of lightweight concrete. When the density of concretes decrease by 200 kg/m³, slump values decrease by about 20 to 30 mm with lightweight concrete mixtures using maximum particle size of 0.63 mm, while slump values decrease by about 40 mm with the mixtures using maximum particle size of 20 mm. At the same density, the compressive strength of the structural polystyrenre concrete significantly decreased when the coarse aggregate diameter greater than 10 mm. Therefore, coarse aggregates with diameter size are smaller than 10 mm was recommended to use for matrix. In the result, expanded polystyrene concrete with density from 1,400 kg/m³ to 2,000 kg/m³ and compressive strength more than 20 MPa for structural application was made.

Erratum to: “Determination of the principal parameter of ultrasonic pulse velocity and compressive strength of lightweight concrete by using variance method”

Erratum to: “Determination of the principal parameter of ultrasonic pulse velocity and compressive strength of lightweight concrete by using variance method”

Effect of Calcium Carbonate on Compressive Strength and Physical Properties of Alkali-Activated Lightweight Concrete

This study presents the compressive strength and physical properties of alkali-activated lightweight concrete. Alkali-activated lightweight concrete was synthesized with fly ash, calcium carbonate and sodium hydroxide solution. Calcium carbonate was designed to replace part of fly ash at 5 and 10 wt.%. Sodium hydroxide solution at 5, 7.5 and 10 M was used as a liquid solution. Liquid to ash ratio (L/A ratio) at 0.45 was designed and aluminium powder was used as a foaming agent. The results showed that, the compressive strength of alkali-activated lightweight concrete made with fly ash was increased with NaOH concentration increased. The maximum compressive strength at 6.0 MPa was obtained from 10M NaOH mixture. For fly ash-calcium carbonate system, the compressive strength of lightweight concrete was improved when containing calcium carbonated, especially at 5 and 7.5 M NaOH mixtures. The maximum of compressive strength at 8.1 MPa and bulk density were obtained from the 5 wt.% calcium carbonated with 10M NaOH mixture. Water absorption and voids of all mixtures trend to decrease with increased NaOH concentration. XRD showed the sodium aluminum silicate hydrated as an alkali-activated product and composed of Si/Al atomic ratio at 2.1 and Na/Al atomic ratio at 1.4, respectively. Bulk density and compressive strength of alkali-activated lightweight concrete made with both fly ash and fly ash-calcium carbonated were acceptable in accordance with the specified criteria of TIS 2601. The well pore structure distribution of alkali-activated lightweight concrete was acceptable.

Characterization of Lightweight Concrete Produced from Plastics Waste - Polystyrene and EVA

In this paper, the lightweight concrete made from polystyrene and ethylene vinyl acetate (EVA) waste was studied. EVA waste from footwear industry and waste polystyrene were used as an aggregate in the lightweight concrete. Each of the plastic wastes was used alone (as a sole aggregate) or in combination with the other in a ratio of 1:3, 1:1 and 3:1. The water-cement ratio of 0.50 and the dose of cement – 175 kg·m-3 were used for all mixtures. Test results showed that the bulk density and the thermal conductivity of lightweight concrete tended to increase with increasing EVA waste content. The maximum compressive strength of lightweight concrete was reached with the waste materials in a ratio of 1:1. Based on the results, the application of EVA waste as lightweight filler showed a good possibility for use in the lightweight concrete.

Compressive Strength of Lightweight Concrete with the Use of Waste Polyethylene Terephthalate Bottles

Compressive Strength of Lightweight Concrete with the Use of Waste Polyethylene Terephthalate Bottles

Optimizing Mix Proportion of Lightweight Concrete Containing Plastic Waste by Taguchi Method

In this study, mix proportion parameters of lightweight concrete (LWC) containing ethyl vinyl acetate (EVA) plastic waste from footwear manufacture were investigated by employing Taguchis method and ANOVA statistics. The mixtures were designed in a L9 orthogonal array with four factors viz., water/cement, water content, EVA content and sand/cement. The results showed that EVA content and water/cement ratio had the significant effect on density and compressive strength of LWC. The density and compressive strength of the LWC containing EVA waste ranged from 1172 to 1441 kg/m3 and from 3.5 to 10.8 MPa, respectively. It can be concluded that the obtained LWC can be classified as masonry concrete. The best possible levels for mix proportions were determined to optimize density and compressive strength of the samples.

경량콘크리트와 GFRP 보강근의 부착 특성

FRP 보강근을 사용한 경량콘크리트 구조체는 부식방지 및 자중감소의 효과를 동시에 기할 수 있는 이점이 있어서 추후 그 활용이 기대될 수 있다. 그러나 경량콘크리트와 FRP 보강근을 사용하여 보강근의 내부슬립 없이 외력에 저항할 수 있는 구조체를 만들기 위해서는 경량콘크리트와 FRP 보강근 사이의 부착특성을 파악하는 것이 대단히 중요하다. 그동안 보통콘크리트와 FRP 보강근 사이의 부착거동에 대하여는 많은 연구가 있어 왔으나 경량콘크리트와 FRP 보강근 사이의 부착거동에 대하여는 현재까지 연구결과가 대단히 부족한 실정이다. 따라서 본 연구에서는 경량콘크리트와 보강근 표면에 나선형태의 이형을 갖는 GFRP 보강근 사이의 부착특성을 조사하였다. 비교목적으로 보강근 종류, 콘크리트 종류, 경량콘크리트 강도종류의 실험변수를 고려하여 인발실험체들을 제작하고 실험을 행하였다. 실험분석 결과, 보통콘크리트와 철근을 사용한 실험체의 부착강도를 1.0으로 하였을 때 경량콘크리트와 나선형태의 이형을 갖는 GFRP 보강근을 사용한 실험체의 부착강도는 0.49로 나타났다. FRP reinforced lightweight concrete structures can offer corrosion resistance and weight reduction effect simultaneously, so practical use of the structures may be expected afterwards. But to make concrete structures using lightweight concrete and FRP bar, that can resist external forces without internal slip of the FRP bar, it is very important to understand bond characteristic between lightweight concrete and FRP bar. During that time, a lot of studies for bond behaviors of FRP bar in normal concrete were conducted, but studies for bond behavior of FRP bar in lightweight concrete are very limited to date. So, bond characteristic between lightweight concrete and helically deformed GFRP bar was investigated in this study. Three main parameters were considered in experimental investigation: type of rebar, concrete type, and compressive strength of lightweight concrete. As an experimental result, it could be known that bond strength of helically deformed GFRP bar in lightweight concrete was 0.49 times bond strength of steel reinforcement in normal concrete.

Variance analysis of crack characteristics of structural lightweight concrete containing silica fume exposed to high temperature

In this study, crack characteristics of structural lightweight concrete containing silica fume exposed to high temperature were investigated experimentally and statistically. Mixtures incorporating 0%, 10%, 20% and 30% silica fume were prepared. After being heated to temperatures of 200, 400 and 800°C, respectively, the compressive strength of lightweight concrete was determined. This article applied the Taguchi method using L32 (21×49) orthogonal array for compressive strength and L16 (41×211) orthogonal array for crack characteristics to reduce the numbers of experiment. Three control factors (percentage of silica fume, heating intensity and cement content) were used in this study. The level of importance of these parameters on compressive strength and crack characteristics was determined by using analysis of variance (Anova) method.

Properties of fly-ash lightweight aggregate concretes

Lightweight concrete with sintered fly-ash aggregates was compared with that of normal weight concrete with granite aggregates for various water/binder ratios starting from 0·30 to 0·50. They both had the same mixture proportion by volume and the only difference between them was the coarse aggregate used. Test results indicated that when granite aggregates have been replaced completely with lightweight aggregates, a reduction of 20% in the density of concretes was observed. Lightweight concrete exhibited higher workabilities than the corresponding normal weight concrete mixtures. With the exception of the elastic modulus all the other properties such as compressive strength, splitting tensile strength and chloride permeability of the lightweight concrete mixtures were comparable with normal weight concrete mixtures at water/binder ratios of 0·45 and 0·50. The ratios of splitting tensile strength to compressive strength of lightweight concrete were found to be similar to that of normal weight concrete.

Resistance Model of Lightweight Concrete Members

The objective of this study is to develop a resistance model for lightweight concrete (LWC) beams and slabs and compare it with normalweight concrete (NWC) beams and slabs using new material and component test data. The focus is on the development of statistical parameters for bending moment capacity and shear capacity. Resistance parameters can then serve as a basis for the determination of rational resistance factors for LWC. Load carrying capacity (resistance) is considered a product of three random variables representing the uncertainty in material properties, dimensions, and geometry (fabrication factor) and analytical model (professional factor). In general, it was observed that the compressive strength of LWC is similar to that of NWC and, in some cases, is even better. However, the lab tests of beams and slabs show that the current shear design procedure is less conservative for LWC compared to NWC. Therefore, the resistance factor for LWC has to be revised.

Size and shape effects on compressive strength of lightweight concrete

In this study, the size and aspect ratio effects on the compressive strength of lightweight concrete were examined using nine laboratorial concrete mixes and three ready-mixed concrete batches. At each concrete mix, the aspect ratios of specimens with circular or square sections were 1.0 and 2.0. The lateral dimension of specimens ranged between 50 and 150mm at each laboratorial concrete mix, while it varied from 50 to 400mm at each ready-mixed concrete batch. The present study also proposed generalized prediction models for the size effect based on the crack band theory of fracture mechanics, which can cover important influencing parameters such as the aspect ratio and lateral depth of the specimen and the unit weight of concrete. Test results showed that the crack band zone in lightweight concrete specimens was more localized with poor crack distribution than in normal-weight concrete specimens, regardless of the geometrical dimensions of the specimens. As a result, the size effect was stronger with the decrease of the concrete unit weight, and this trend was more notable in specimens with an aspect ratio of 2.0 than in those with an aspect ratio of 1.0. The compressive strength predictions of concrete obtained from the present models are in good agreement with the test results including a total of 1661 data. The trend of the size effect against different parameters as predicted by the present models has a consistent agreement with that observed from experimental results.

Determination of the principal parameter of ultrasonic pulse velocity and compressive strength of lightweight concrete by using variance method

Experiments are usually made to finding maximum ultrasonic pulse velocity and compressive strength of lightweight concrete. In this study, ultrasonic pulse velocity and compressive strength of lightweight concrete made with scoria aggregate, silica fume and fly ash was investigated experimentally and statistically. This article adopts Taguchi approach. The Taguchi method has been used to determine the optimum conditions and to reduce the numbers of experiments. Four control factors (maximum size of aggregate, curing conditions, mineral admixtures and curing time) for this study were used. The level of importance of these parameters on ultrasonic pulse velocity and compressive strength was determined by using analysis of variance (Anova) method.

The Effect of Aggregate Volume Ratio on the Elastic Modulus and Compressive Strength of Lightweight Concrete

The Effect of Aggregate Volume Ratio on the Elastic Modulus and Compressive Strength of Lightweight Concrete