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 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.

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.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

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.

scholarly journals Effect of Curing Method on Properties of Lightweight Foamed Concrete

2018 ◽  
Vol 7 (2.29) ◽  
pp. 927 ◽  
Author(s):  
Bishir Kado ◽  
Shahrin Mohammad ◽  
Yeong Huei Lee ◽  
Poi Ngian Shek ◽  
Mariyana Aida Ab Kadir
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Absorption ◽  
Precast Concrete ◽  
Construction Materials ◽  
Splitting Tensile Strength ◽  
Structural Members ◽  
Lightweight Construction ◽  
Foamed Concrete ◽  
Curing Method

Lightweight construction is aimed to achieve a sustainable feature by reducing transportation frequency and construction materials usage during construction phase. Lightweight precast concrete may serve an alternative for the lightweight construction. There are rarely application can be found for structural members as lightweight panels always to be used for secondary or non-load bearing members. This paper presents an experimental study on properties (compressive strength, splitting tensile strength, water absorption) of lightweight foamed concrete (LFC) at two different curing methods. LFC with densities of 1500, 1700, and 1800 kg/m3, cement-sand ratio of 2:1 and water-cement ratio of 0.5 were investigated. The results showed LFC can be produced with the properties ofdensity range of 1500 to 1800 kg/m3 and corresponding compressive strength of 10 to 39 MPa. The higher the density of LFC, the less the water absorption for all the curing method considered, the highest and the lowest water absorption was 11.3% and 2.0% for 1500 kg/m3 cured in water and 1800 kg/m3 cured in air respectively. Compressive strength of LFC increases with age and density while water cured LFC has high compressive strength. Splitting tensile strength increases with density of LFC, but air cured LFC has more splitting tensile strength than water cured of the same density. The highest splitting tensile strength recorded was 3.92 MPa for 1800 kg/m3 cured in air, which was about 16% of its compressive strength at 28 days of curing age. These properties are important and can be applied to LFC precast structural members with air or water curing method which have less references for LFC in structural usage.  

scholarly journals The Effect of Nano Metakaolin Material on Some Properties of Concrete

2013 ◽  
Vol 6 (1) ◽  
pp. 50-61
Author(s):  
Amer M. Ibrahem ◽  
Shakir A. Al-Mishhadani ◽  
Zeinab H.Naji
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Thermal Activation ◽  
Ordinary Portland Cement ◽  
Splitting Tensile Strength ◽  
Kaolin Clay ◽  
Cement Ratio ◽  
Water Cement Ratio

This investigation aimed to study the effect of nano metakaolin ( NMK ) on some properties (compressive strength ,splitting tensile strength & water absorption ) of concrete. The nano metakaolin (NMK) was prepared by thermal activation of kaolin clay for 2 hours at 750 Ċ. The cement used in this investigation consists of ordinary Portland cement (OPC). The OPC was partially substituted by NMK of ( 3, 5 & 10%) by weight of cement. The C45 concrete was prepared , using water/cement ratio ( W/c) of (0.53) .The Water absorption was tested at 28 days while the tests (compressive strength ,splitting tensile strength) were tested at ages of (7, 28, 60,& 90) days . The compressive strength and splitting tensile strength of concrete with NMK were higher than that of reference concrete with the same W/c ratio.The improvement in the compressive strength when using NMK was (42.2, 55.8 , 63.1% ) at age 28 days for ( 3%, 5%, &10% ) replacement of NMK respectively whereas the improvement in the splitting tensile strength was (0% , 36% & 46.8 %) at age of 28 days when using (3%, 5%, &10% ) NMK respectively. The improvement in the water absorption was (16.6%, 21.79%, &25.6 ) when using (3, 5, &10% )NMK.

Experiment and Research on Mechanic Behavior of Concrete with Different Addition Amounts of Polypropylene Fibers

2012 ◽  
Vol 430-432 ◽  
pp. 1064-1067
Author(s):  
Yu Zhi Chen ◽  
Wei Hong Xuan ◽  
Xiao Hong Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Polypropylene Fiber ◽  
Polypropylene Fibers ◽  
Flexural Tensile Strength ◽  
Axial Compressive Strength ◽  
Low Dosage

The effect of the different addition amounts of polypropylene fibers on the basic mechanical properties of concrete were investigated in this paper. The results show that the flexural tensile strength of concrete changed slightly after adding low-dosage polypropylene fiber(0.04%～0.16%); Axial compressive strength and flexural tension modulus decreased, limiting flexural strain increased gradually with the amounts of fibers rising.

Experimental Study on Axial Tensile Strength of Low Volume Fraction of Ternary Hybrid Fiber Reinforced Concrete

2014 ◽  
Vol 906 ◽  
pp. 329-334
Author(s):  
Yu Ting Zhu ◽  
Dong Tao Xia ◽  
Bo Ru Zhou
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Strength Test ◽  
Splitting Tensile Strength ◽  
National Standard ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Advantages And Disadvantages

In this paper, according to the national standard and testing methods,the direct tension strength,splitting tensile strength and cubic compressive strength test were carried out for 8 different groups of hybrid fiber (containing steel fiber, macro-polypropylene fiber and dura fiber) reinforced HPC specimens.The results showed that when the volume proportion of ternary hybrid fiber was less than 1%, there was not obvious influence for the concrete compressive strength, but the splitting tensile strength increased by 26% ~ 69%; the ratio between splitting tensile strength and compressive strength for HFRC increased to 1/12~1/9. When added 0.7% steel fiber, 0.19% macro-polypropylene fiber and 0.11% dura fiber, the confounding effect was the best. Based on the advantages and disadvantages of tensile splitting strength and direct tensile strength test and the results of tests, the concept of equivalent tensile strength and calculative formula was put forward .

scholarly journals Impact of twisting high-performance polyethylene fibre bundle reinforcements on the mechanical characteristics of high-strength concrete

2019 ◽  
Vol 69 (334) ◽  
pp. 184
Author(s):  
Y. Zhang ◽  
L. Yan ◽  
S. Wang ◽  
M. Xu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Strain Rate ◽  
Uniform Distribution ◽  
Dynamic Compression ◽  
Splitting Tensile Strength ◽  
Fibre Reinforced Concrete ◽  
Compressive Strength Of Concrete ◽  
Concrete Matrix

The quasi-static and dynamic mechanical behaviours of the concrete reinforced by twisting ultra-high molecular weight polyethylene (UHMWPE) fibre bundles with different volume fractions have been investigated. It was indicated that the improved mixing methodology and fibre geometry guaranteed the uniform distribution of fibres in concrete matrix. The UHMWPE fibres significantly enhanced the splitting tensile strength and residual compressive strength of concrete. The discussions on the key property parameters showed that the UHMWPE fibre reinforced concrete behaved tougher than the plain concrete. Owing to the more uniform distribution of fibres and higher bonding strength at fibre/matrix interface, the UHMWPE fibre with improved geometry enhanced the quasi-static splitting tensile strength and compressive strength of concrete more significantly than the other fibres. The dynamic compression tests demonstrated that the UHMWPE fibre reinforced concrete had considerable strain rate dependency. The bonding between fibres and concrete matrix contributed to the strength enhancement under low strain-rate compression.

scholarly journals Experimental Investigation on Mechanical Properties of Hybrid Fiber Reinforced Quaternary Cement Concrete

2015 ◽  
Vol 10 (4) ◽  
pp. 155892501501000
Author(s):  
Ramesh Kanagavel ◽  
K. Arunachalam
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Impact Resistance ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Cement Concrete ◽  
Split Tensile Strength ◽  
Polypropylene Fiber Reinforced Concrete

Mechanical properties of quaternary blending cement concrete reinforced with hybrid fibers are evaluated in this experimental study. The steel fibers were added at volume fractions of 0.5%, 1%, and 1.5 % and polypropylene fibers were added at 0.25% and 0.5% by weight of cementitious materials in the concrete mix individually and in hybrid form to determine the compressive strength, split tensile strength, flexural strength and impact resistance for all the mixes. The experimental results revealed that fiber addition improves the mechanical properties and also the ductility and energy absorption of the concrete. The results also demonstrate that the hybrid steel – polypropylene fiber reinforced concrete performs better in compressive strength, split tensile strength, flexural strength and impact resistance than mono steel and mono polypropylene fiber reinforced concrete.

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