scholarly journals Mechanical Properties of Chopped Basalt Fiber-Reinforced Lightweight Aggregate Concrete and Chopped Polyacrylonitrile Fiber Reinforced Lightweight Aggregate Concrete

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1715 ◽  
Author(s):  
Yusheng Zeng ◽  
Xianyu Zhou ◽  
Aiping Tang ◽  
Peng Sun
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Shear Strength ◽  
Water Absorption ◽  
Basalt Fiber ◽  
Lightweight Aggregate ◽  
Splitting Tensile Strength ◽  
Lightweight Aggregate Concrete ◽  
Polyacrylonitrile Fiber ◽  
Aggregate Concrete

In this study, an experimental investigation was conducted on the mechanical properties of lightweight aggregate concrete (LWAC) with different chopped fibers, including basalt fiber (BF) and polyacrylonitrile fiber (PANF). The LWAC performance was studied in regard to compressive strength, splitting tensile strength and shear strength at age of 28 days. In addition, the oven-dried density and water absorption were measured as well to confirm whether the specimens match the requirement of standard. In total, seven different mixture groups were designed and approximately 104 LWAC samples were tested. The test results showed that the oven-dried densities of the LWAC mixtures were in range of 1.819–1.844 t/m3 which satisfied the definition of LWAC by Chinese Standard. Additionally, water absorption decreased with the increasing of fiber content. The development tendency of the specific strength of LWAC was the same as that of the cube compressive strength. The addition of fibers had a significant effect on reducing water absorption. Adding BF and PANF into concrete had a relatively slight impact on the compressive strength but had an obvious effect on splitting tensile strength, flexural strength and shear strength enhancement, respectively. In that regard, a 1.5% fiber volume fraction of BF and PANF showed the maximum increase in strength. The use of BF and PANF could change the failure morphologies of splitting tensile and flexural destruction but almost had slight impact on the shear failure morphology. The strength enhancement parameter β was proposed to quantify the improvement effect of fibers on cube compressive strength, splitting tensile strength, flexural strength and shear strength, respectively. And the calculation results showed good agreement with test value.

Experiment on the Mechanical Performance of Fiber Lightweight Aggregate Concrete after Freeze-Thaw and Elevated Temperature

2014 ◽  
Vol 919-921 ◽  
pp. 1790-1793 ◽  
Author(s):  
Bo Cheng ◽  
Jing Huang ◽  
Wen Ting Jiang ◽  
Jian Min Wang
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Room Temperature ◽  
Mechanical Performance ◽  
Lightweight Aggregate ◽  
Splitting Tensile Strength ◽  
Lightweight Aggregate Concrete ◽  
Polyacrylonitrile Fiber ◽  
Aggregate Concrete ◽  
Freeze Thaw

Experiment on the compressive strength and splitting tensile strength of fiber lightweight aggregate concrete (FLWAC) after freeze-thaw cycling and high temperature was tested through blending polyvinyl alcohol fiber (PVAF) and polyacrylonitrile fiber (PANF) in aggregate concrete respectively. Five temperature levels, room temperature, 200°C, 400°C, 600°Cand 800°C were selected to heat the FLWAC test blocks after 25 times of freeze-thaw cycling. The micro-structure of FLWAC was observed through SEM. The experiment results show that, the cubic compressive strength of FLWAC is improved when the temperature is above 200°C, and the splitting tensile strength of FLWAC is obviously improved between the ranges from room temperature to 600°C. Blending fiber can weaken the brittle fracture performance of LWAC after freeze-thaw cycling at the peak loading state. However, the mass loss doesn’t have obvious improvement before and after 25 number of freeze-thaw cycling.

Mechanical Properties of Fiber Reinforced Lightweight Aggregate Concrete

2011 ◽  
Vol 477 ◽  
pp. 274-279 ◽  
Author(s):  
Yi Xu ◽  
Lin Hua Jiang ◽  
Hong Qiang Chu ◽  
Lei Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Water Hyacinth ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Lightweight Aggregate ◽  
Splitting Tensile Strength ◽  
Lightweight Aggregate Concrete ◽  
Fiber Types

In this study, the effects of fiber types on the mechanical properties of lightweight aggregate concretes were investigated. Three types of fibers, namely, polypropylene fiber, steel fiber and water hyacinth (Eichhornia crassipes) fiber, and two types of lightweight aggregates, namely, expanded polystyrene and ceramsite were used. The compressive strength and splitting tensile strength of concretes were tested. The results show that both the compressive strength and the splitting tensile strength were improved by adding a reasonable volume of steel fiber and polypropylene fiber into LWAC. The addition of water hyacinth fiber had little effect on the compressive strength of LWAC, while a little increase was observed in the splitting tensile strength.

Mechanical Properties of Lightweight Alum Sludge Aggregate Concrete

2015 ◽  
Vol 754-755 ◽  
pp. 413-416 ◽  
Author(s):  
Nur Quraatu’ Aini Mohd Rajin ◽  
Roszilah Hamid
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Content Increase ◽  
Split Tensile Strength ◽  
Aggregate Concrete ◽  
Alum Sludge ◽  
Better Than

Disposal of alum sludge (AS) in such an economical and environmental friendly way is a major challenge that water treatment plants around the globe had to deal with. AS cannot be dumped into landfills as it contains heavy metals which are harmful to the environment. In this study, alum sludge is utilised as partial replacements (0, 5 and 10%) of natural granite coarse aggregate (by mass) to form a lightweight concrete. The water/cement ratio is 0.65. The water absorption of the alum sludge is 22.06%. The slump, density, compressive strength and split tensile strength of the lightweight alum sludge aggregate concrete (LASAC) reduce as the AS aggregate content increase. The density of the 10% AS aggregate concrete is 2185.3 kg/m3. The compressive strength reduced from 25.6 MPa to 16.7 MPa and 14.2 MPa at 0, 5 and 10% replacement of AS aggregate respectively. The 2.18 MPa tensile strength of the control concrete reduced to 1.53 MPa at 10% replacement of AS aggregate. But as for the flexural strength, it increases from 5.42 MPa for the control up to 5.55 MPa and 5.63 MPa for 5 and 10% replacement of AS aggregate respectively. Results show that strength of alum sludge lightweight aggregate concrete is better than lightweight crumb tyre aggregate concrete and is at par with oil palm coconut shell aggregate concrete.

scholarly journals Preparation, Performance Test, and Microstructure of Composite Modified Reinforced Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Shi Hu ◽  
Ying Xu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Water Absorption ◽  
Absorption Rate ◽  
Impact Resistance ◽  
Polypropylene Fiber ◽  
Splitting Tensile Strength ◽  
Aggregate Concrete ◽  
Flexural Tensile Strength

To investigate whether the compound modification means which mixes modified Polyvinyl chloride (PVC) aggregate and polypropylene fiber in concrete could gain “positive hybrid effect” and cope with more sophisticated engineering circumstances, four groups of test specimens were prepared: concrete doped with unmodified PVC aggregate, concrete doped with modified PVC aggregate, concrete doped with unmodified PVC aggregate and polypropylene fiber, and concrete doped with modified PVC aggregate and polypropylene fiber. The fiber content is 0.9 kg/m3, the modified solution content is 1 mol/L NaOH, and the replacement amount of PVC fine aggregate in replacement sand is 0%, 5%, 10%, 20%, and 30%. Mechanical property and durability tests were carried out to compare and analyze the measured compressive strength, splitting tensile strength, flexural tensile strength, water absorption rate, and impact failure energy. Moreover, scanning electron microscopy and XRD diffraction were used to analyze micromorphology and crystal structure of concrete. The test results demonstrate that as the content of PVC aggregate increases, the compressive strength, splitting tensile strength, and flexural tensile strength of the concrete decrease significantly, while the brittleness is improved. Meanwhile, the water absorption rate increases and the impact resistance shows an approximately linear increase trend. Under the same content of PVC aggregate, the most effective way to improve compressive strength is to use modified PVC aggregate. The rapid decrease of compressive strength caused by PVC aggregate can be effectively delayed by doping polypropylene fiber and modified PVC aggregate. Adding polypropylene fiber or using the modified PVC aggregate can improve the brittleness, tensile strength, flexural tensile strength, and impact resistance, but they have different modification and reinforcement effects. The concrete prepared by doping polypropylene fiber and modified PVC aggregate has better performance in tensile strength, flexural tensile strength, brittleness, and impact resistance, and the water absorption and the compressive strength of the concrete are enhanced compared with the normal group. Therefore, composite modified reinforced concrete doped with modified PVC aggregate-polypropylene fiber has broad application prospects.

scholarly journals The Effects of Additives to Lightweight Aggregate on the Mechanical Properties of Structural Lightweight Aggregate Concrete

2021 ◽  
Vol 31 (1) ◽  
pp. 139-160
Author(s):  
Mehdi Khoshvatan ◽  
Majid Pouraminia
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Specific Gravity ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Lightweight Aggregates ◽  
Structural Concrete ◽  
Aggregate Concrete ◽  
Structural Lightweight Aggregate Concrete

Abstract In the paper, the effects of different percentages of additives (perlite, LECA, pumice) on the mechanical properties of structural lightweight aggregate concrete were tested and evaluated. For the research, 14 mixing designs with different amounts of aggregate, water, and cement were made. Experimental results showed that the specific gravity of lightweight structural concrete made from a mixture of LECA, pumice, and perlite aggregates could be 25-30% lighter than conventional concrete. Lightweight structural concrete with a standard specific gravity can be achieved by using a combination of light LECA with perlite lightweight aggregates (LA) and pumice with perlite in concrete. The results indicated that LECA lightweight aggregates show more effective behavior in the concrete sample. Also, the amount of cement had a direct effect on increasing the strength regardless of the composition of LAs. The amount of cement causes compressive strength to increase. Furthermore, the stability of different experimental models increased from 156 to 345 kg m 3 while increasing the amount of cement from 300 to 400 kg m 3 in the mixing designs of LECA and perlite for W/C ratios of 0.3, 0.35, and 0.4. For a fixed amount of cement equal to 300 kg, the compressive strength is reduced by 4% by changing the water to cement ratio from 0.5 to 0.4. The compression ratios of strength for 7 to 28 days obtained in this study for lightweight concrete were between 0.67-0.8. Based on the rate of tensile strength to compressive strength of ordinary concretes, which is approximately 10, this ratio is about 13.5 to-17.8 in selected and optimal lightweight concretes in this research, which can be considered good indirect tensile strength for structural lightweight concretes.

Study on Hybrid Fiber Reinforced Lightweight Aggregate Concrete

2013 ◽  
Vol 477-478 ◽  
pp. 949-952
Author(s):  
Yan Chen
Keyword(s):  
Tensile Strength ◽  
Basalt Fiber ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Hybrid Fiber ◽  
Aggregate Concrete ◽  
Concrete Mix ◽  
Fiber Materials ◽  
Pva Fiber ◽  
Better Than

For lightweight aggregate concrete, fiber materials can reinforce its toughness and strength better and improve its segregation degree greatly. Specifically, as the experiment indicates, the fluidity of concrete mix decreases slightly after 0.5% basalt fiber and 0.5% PVA fiber are incorporated into the concrete with FA ceramsite as lightweight aggregate. However, its segregation degree reduces about 50%. And its 28d cubic compressive strength increases 0.7% and 28d splitting tensile strength increases 12.7%. Therefore, this effect is better than that of adding only one kind of fiber.

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

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.

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

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.

scholarly journals Feasibility of Using Nanoparticles of SiO2 to Improve the Performance of Recycled Aggregate Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Khaleel H. Younis ◽  
Shelan M. Mustafa
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Splitting Tensile Strength ◽  
Recycled Aggregate Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Demolition Waste ◽  
Aggregate Concrete ◽  
Natural Aggregate

The aim of this paper was to examine the feasibility of using nanoparticles of SiO2 (nanosilica) to improve the performance of recycled aggregate concrete (RAC) containing recycled aggregate (RA) derived from processing construction and demolition waste of concrete buildings. The examined properties include compressive strength, splitting tensile strength, and water absorption. The study also includes examining the microstructure of RA and RAC with and without nanoparticles of SiO2. In total, nine mixes were investigated. Two mixes with RA contents of 50% and 100% were investigated and for each RA content; three mixes were prepared with three different nanoparticles dosages 0.4%, 0.8%, and 1.2% (by mass of cement). A control mix with natural aggregate (NA) was also prepared for comparison reasons. The results show that nanoparticles of silica can improve the compressive strength, tensile strength, reduce the water absorption, and modify the microstructure of RAC.

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