Influence of Aggregate Gradation on the Engineering Properties of Lightweight Aggregate Concrete

Expanded shale lightweight aggregates, as the coarse aggregates, were used to produce lightweight aggregate concrete (LWAC) in this research. At the fixed water-cement ratio, paste quantity, and aggregate volume, the effects of various aggregate gradations on the engineering properties of LWAC were investigated. Comparisons to normal-weight concrete (NWC) made under the same conditions were carried out. From the experimental results, using normal weight aggregates that follow the specification requirements (standard gradation) obtained similar NWC compressive strength to that using uniform-sized aggregates. However, the compressive strength of LWAC made using small uniform-sized aggregates was superior to that made from standard-grade aggregates. This is especially conspicuous under the low water-cement ratio. Even though the workability was affected, this problem could be overcome with developed chemical additive technology. The durability properties of concrete were approximately equal. Therefore, it is suggested that the aggregate gradation requirement of LWAC should be distinct from that of NWC. In high strength LWAC proportioning, following the standard gradation suggested by American Society for Testing and Materials (ASTM) is optional.

Download Full-text

Size Effect in Compressive Strength Tests of Cored Specimens of Lightweight Aggregate Concrete

Materials ◽

10.3390/ma13051187 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1187 ◽

Cited By ~ 1

Author(s):

Lucyna Domagała

Keyword(s):

Compressive Strength ◽

Scale Effect ◽

Lightweight Aggregate ◽

Normal Weight ◽

Cement Matrix ◽

Lightweight Aggregate Concrete ◽

Core Diameter ◽

Aggregate Concrete ◽

Normal Weight Concrete ◽

Strength Tests

The aim of this paper is to discuss the unrecognized problem of the scale effect in compressive strength tests determined for cored specimens of lightweight aggregate concrete (LWAC) against the background of available data on the effect for normal-weight concrete (NWAC). The scale effect was analyzed taking into consideration the influence of slenderness (λ = 1.0, 1.5, 2.0) and diameter (d = 80, 100, 125, and 150 mm) of cored specimens, as well as the type of lightweight aggregate (expanded clay and sintered fly ash) and the type of cement matrix (w/c = 0.55 and 0.37). The analysis of the results for four lightweight aggregate concretes revealed no scale effect in compressive strength tests determined on cored specimens. Neither the slenderness, nor the core diameter seemed to affect the strength results. This fact should be explained by the considerably better structural homogeneity of the tested lightweight concretes in comparison to normal-weight ones. Nevertheless, there were clear differences between the results obtained on molded and cored specimens of the same shape and size.

Download Full-text

Effect of mixing ingredient on workability and compressive strength of palm oil clinker lightweight concrete containing palm oil fuel ash

Challenge Journal of Concrete Research Letters ◽

10.20528/cjcrl.2018.04.002 ◽

2018 ◽

Vol 9 (4) ◽

pp. 110

Author(s):

Nur Azzimah Binti Zamri ◽

Khairunisa Muthusamy ◽

Andri Kusbiantoro

Keyword(s):

Palm Oil ◽

Lightweight Aggregate ◽

Lightweight Aggregate Concrete ◽

Palm Oil Fuel Ash ◽

Aggregate Concrete ◽

Cement Ratio ◽

Water Cement Ratio ◽

Concrete Production ◽

Fuel Ash ◽

Oil Fuel

Palm oil industry is one of the important industry that contribute to the country’s prosperity. This flourishing industry however also causes environmental problems namely air pollution, soil degradation as well as water pollution due to waste disposal issue. At the same time, intensive cement production and granite mining is damaging the environment and natural habitats. Hence, various efforts have been made by researchers to minimize the effect of pollution including integrating oil palm wastes in construction as building materials. In this study, granite aggregate was fully replaced by palm oil clinker (POC) in lightweight aggregate concrete production. In order to reduce the utilization of cement in concrete, palm oil fuel ash (POFA) was ground to improve its pozzolanic reactivity to partially replace cement in lightweight aggregate concrete. From this investigation, the best performance concrete was attributed by POC LWAC with 20% POFA when the water cement ratio and superplasticizer are 0.45 and 1.0%. Inclusion of water cement ratio and superplasticizer of 0.35 and 0.8% would adversely affects the workability and strength of POC LWAC with POFA.

Download Full-text

Experiment Study on the Compressive Strength of Combined Aggregate Concrete

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.507.406 ◽

2014 ◽

Vol 507 ◽

pp. 406-409

Author(s):

Hua Cheng Nie ◽

Yan Kun Zhang ◽

Biao Zhang ◽

Shao Jie Shen ◽

Jiang Xing Fan

Keyword(s):

Compressive Strength ◽

Lightweight Aggregate ◽

Experiment Study ◽

Replacement Ratio ◽

Aggregate Concrete ◽

Cement Ratio ◽

Water Cement Ratio ◽

Main Factor

Base on the experiment, the cube compressive strength of the combined aggregate concrete is studied in the paper. The results show that the strength of combined aggregate concrete increases with the decreasing amounts of lightweight aggregate, and the water-cement ratio and the replacement ratio of lightweight aggregate are the main factor on the strength of combined concrete. According to the experiment results, the formula of the compressive strength of combined concrete is given.

Download Full-text

The Structural Characteristics of Lightweight Aggregate Concrete Beams

Journal of University of Babylon for Engineering Sciences ◽

10.29196/jubes.v27i2.2293 ◽

2019 ◽

Vol 27 (2) ◽

pp. 64-73

Author(s):

Sajjad abdulameer Badar ◽

Laith Shakir Rasheed ◽

Shakir Ahmed Salih

Keyword(s):

Compressive Strength ◽

Ultimate Load ◽

Lightweight Concrete ◽

Concrete Beams ◽

Lightweight Aggregate ◽

Normal Weight ◽

Lightweight Aggregate Concrete ◽

Dry Density ◽

Aggregate Concrete ◽

Clay Bricks

This paper aims to investigate the structural behavior of reinforced lightweight concrete beams. Attapulgite aggregate and crushed clay brick aggregate were used as coarse lightweight aggregate to produce structural lightweight aggregate concrete with 25 Mpa and 43.6 Mpa cube compressive strength and 1805 Kg/m3 and 1977 Kg/m3 oven dry density respectively. The result of reinforced lightweight concrete beams compared with reinforced normal weight concrete beams, which have 50.5 Mpa cylinder compressive strength and 2317 Kg/m3 oven dry density. For each type of concrete two reinforced concrete beams with (1200 mm length × 180 mm height × 140 mm width), one of them tested under symmetrical two-points load STPL (a/d = 2.2) and another one tested under one-point load OPL (a/d=3.3) at 28 days. The experimental program shows that a structural lightweight aggregate concrete can be produced by using Attapulgite aggregate with 25 MPa cube compressive strength and 1805 Kg/m3 oven dry density and by using crushed clay brick aggregate with 43.6 MPa cube compressive strength and 1977 Kg/m3 oven dry density. The weight of Attapulgite aggregate concrete and crushed clay bricks aggregate concrete beam specimens were lower than normal weight aggregate concrete beams by about 20.56% and 13.65% respectively at 28 days. As for the ultimate load capacities of beam specimens, the ultimate load of Attapulgite aggregate concrete beams tested under STPL were lower than that of crushed clay bricks aggregate concrete beams and normal weight aggregate concrete beams by about 4.85% and 5% respectively. While the ultimate load capacities of reinforced Attapulgite concrete beams tested under OPL were lower than that of reinforced crushed clay bricks aggregate concrete beams and reinforced normal weight aggregate concrete beams by about 10.3% and 10.5% respectively. Finally, Attapulgite aggregate concrete and crushed clay bricks aggregate concrete showed ductility and toughness less than that of Normal weight aggregate concrete.

Download Full-text

Thermal Performance of Lightweight Aggregate Concrete Containing Expanded Shale Aggregates

Materials Science Forum ◽

10.4028/www.scientific.net/msf.911.71 ◽

2018 ◽

Vol 911 ◽

pp. 71-76

Author(s):

Chang Seon Shon ◽

Miras Mamirov ◽

Earl M. Stenger ◽

Chul Woo Chung

Keyword(s):

Energy Efficiency ◽

Building Materials ◽

Lightweight Aggregate ◽

Good Alternative ◽

Energy Performance ◽

Normal Weight ◽

Lightweight Aggregate Concrete ◽

Large Temperature ◽

Aggregate Concrete ◽

Expanded Shale

Achieving energy efficiency of building in north part of Kazakhstan is very critical due to the large temperature difference during long harsh and severe winter and short hot summer seasons. Energy efficient building shows significant savings to homeowners including costs reduction from energy, water, waste, and lower operations and maintenance costs. In terms of building materials, lightweight aggregate concrete (LWAC) due to its thermal properties is often used to maintain thermal comfort levels in buildings and to reduce building energy consumption. In this paper, the potential of LWAC to improve the energy performance of building was assessed for LWAC with three different mixture proportions and a normal weight concrete (NWC) for comparison purpose. The energy saving effect of LWAC was simulated using OpenStudio software tools with an EnergyPlus engine. Moreover, annual heat loss and amount of heat transfer of construction wall of building were calculated. Results showed that LWAC can improve the energy efficiency of building and thus the use of LWAC can be a good alternative to the traditional NWC.

Download Full-text

Performance of Lightweight Aggregate Concrete Containing Expanded Polystyrene, Cinder and Silica Fume

Journal of Computational and Theoretical Nanoscience ◽

10.1166/jctn.2020.9068 ◽

2020 ◽

Vol 17 (9) ◽

pp. 4311-4317

Author(s):

M. L. Harish ◽

H. Narendra ◽

Md. Rizwan Tahashildar

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Silica Fume ◽

Lightweight Aggregate ◽

Normal Weight ◽

Expanded Polystyrene ◽

Lightweight Aggregate Concrete ◽

Split Tensile Strength ◽

Aggregate Concrete ◽

Optimal Mix

Lightweight aggregate concrete is developed by substituting normal weight aggregate either fully or partially based on required strength and density. Expanded polystyrene (EPS) bead is a type of low density material, which also has good energy-absorbing characteristics and can be used as light weight aggregate in concrete. In the present study, Structural lightweight aggregate concrete (SLWAC) was produced by fully replacing normal weight aggregate with combinations of EPS beads to Cinder by the ratio 20:80, 40:60, 60:40, 80:20 respectively and Silica fume was used as supplementary cementitious material. The resulting concrete had strength variation between 24.85 to 12.01 MPa, and the density variation of 1896 to 1664 kg/m3. Considering strength and density criteria 40:60 ratios was observed as the optimal mix. The Compressive strength acquired by concrete was inversely proportional to the volume of EPS beads. Effect of fibres on mechanical properties such as flexural strength, compressive strength, and split-tensile strength was investigated on optimal mix by using polypropylene fibres, it was observed that a 13.24% increase in flexural strength at 1% fibres, 8.41% increase in Compressive strength at 1% fibres and 23.11% increase in split-tensile strength at 1% fibres. Along with these, durability tests such as water absorption and permeability tests were performed, the performance of this concrete in water absorption test and permeability is well within the acceptable limits as the EPS ratio in the concrete increased, the absorption and depth of penetration values increased considerably. Microscopic observations were also made to study the interface amongst the cement paste and aggregates. It was revealed that silica fume has influenced significantly in bonding with EPS beads.

Download Full-text

Performance of Lightweight Aggregate Concrete Containing Expanded Polystyrene, Cinder and Ground-Granulated Blast-Furnace Slag

Journal of Computational and Theoretical Nanoscience ◽

10.1166/jctn.2020.9067 ◽

2020 ◽

Vol 17 (9) ◽

pp. 4304-4310

Author(s):

M. L. Harish ◽

H. Narendra ◽

Md. Azam Afzal

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Flexural Strength ◽

Lightweight Aggregate ◽

Normal Weight ◽

Expanded Polystyrene ◽

Lightweight Aggregate Concrete ◽

Split Tensile Strength ◽

Aggregate Concrete ◽

Optimal Mix

Lightweight aggregate concrete is developed by substituting normal weight aggregate either fully or partially based on strength and density required. Expanded polystyrene (EPS) bead is a type of low density material, which also has good energy-absorbing characteristics and can be used as light weight aggregate in concrete. In the present study, Structural lightweight aggregate concrete (SLWAC) was produced by fully replacing normal weight aggregate with combinations of EPS beads to Cinder by the ratio 20:80, 40:60, 60:40, 80:20 respectively. And GGBS was used as supplementary cementitious material. The resulting concrete had strength variation between 29.5 to 11.6 MPa, and the density variation of 2192 to 1701 kg/m3. Considering strength and density criteria 40:60 ratios was observed as the optimal mix. The Compressive strength acquired by concrete was inversely proportional to the volume of EPS beads. Effect of fibers on mechanical properties such as flexural strength, compressive strength, and split-tensile strength was studied on the optimal mix by using polypropylene fibers, it was observed that an 8.78% increase in flexural strength at 1% fibers, 16.5% increase in Compressive strength at 0.5% fibers, and 35.4% increase in split-tensile strength at 1% fibers. Along with this, durability tests such as water absorption and permeability tests were performed, the performance of this concrete in water absorption test is well within the limits but in permeability, it underperformed which confirms that as the EPS ratio in the concrete increased, the absorption and depth of penetration values increased considerably. Microscopic observations were also made to study the interface amongst the cement paste and aggregates. It was revealed that GGBS did not influence significantly on the bonding with EPS beads.

Download Full-text