scholarly journals Mechanical Characteristics of Lightweight Concrete Enhanced by Fly-Ash and Steel Fiber

2019 ◽  
Vol 26 (4) ◽  
pp. 16-25
Author(s):  
Arkan Ahmed ◽  
Bayer Al-Sulayvany ◽  
Muyasser Jomma’h

This research deals with production of light weight aggregate concrete by using clayey stone aggregate, normal material (cement , sand) and some of mineral admixtures (fly ash and steel fiber ). Many trial mix were doing some of these by weighing ratio and others by volumetric ratio . We get light weight aggregate concrete (LWAC) with 24.92 N/ mm2 compressive strength and we improved mechanical properties by adding same percentage of fly ash and steel fiber (0.5 ,1 ,1.5) % of each other as a percentage weighing ratio of cement content . compressive strength increased with (7.8 , 5.2 , 2.9) % , splitting tensile strength increased with (20 ,16.71, 12)% and flexural strength increased with (24.5 , 17.9 , 8) % when adding (0.5 ,1 ,1.5) % of each steel fiber and fly ash respectively. The practical results of the current study indicates that the using clayey stone to produce (LWAC) is success and we can improved mechanical properties of this (LWAC) was produced in this research by adding fly ash and steel fiber with previously percentage.

2013 ◽  
Vol 357-360 ◽  
pp. 944-948
Author(s):  
Jian Gang Niu ◽  
Bo Xiao Li ◽  
Zhen Zhang

Compressive performance test of lightweight aggregate concrete with different quantity of steel fiber and plastics-steel fiber is carried out, and the following conclusions are obtained. It is not obvious that the change of compressive strength when LC30 light weight aggregate concrete mixed with plastics-steel fiber. Compressive strength is enhanced steadily to light weight aggregate concrete with steel fiber, but the amplitude is not large. The compressive deformation and failure characteristic of lightweight aggregate concrete are greatly improved as a result of mixed with plastics-steel fiber and steel fiber, and the failure pattern of lightweight aggregate concrete changed from brittle failure into a certain plastic failure.


2020 ◽  
Vol 165 ◽  
pp. 04040
Author(s):  
Li Yunyun ◽  
Niu Jiangang ◽  
Yang Baosheng ◽  
Li Jingjun

In this study, lightweight aggregate concrete (LWAC) specimens with different plastics-steel fibre volumes were tested to investigate the effect of plastics-steel fibre fraction on the mechanical properties of LWAC through the experimental research and theoretical analysis. The experimental results indicated that incorporation of steel fibre into LWAC can greatly improve such mechanical properties as flexural toughness and impact resistance, but leads to a little effect on compressive strength and flexural strength.


2013 ◽  
Vol 739 ◽  
pp. 251-254
Author(s):  
Ru Jie Huang ◽  
Chen Shi ◽  
Guo Xin Li

Lightweight aggregate concrete has lower density and lower elasticity modulus, so it has better earthquake resistance. But the low strength limited the application of lightweight concrete. Steel fiber can improve the strength of lightweight aggregate concrete. In this paper, the influences of different lengths of steel fiber on the slump, compressive strength, splitting tensile strength and antiflex cracking strength are investigated. The results show that adding steel fiber reduces the workability of the concrete mixture, but it improved the each strength of light weight concrete and different lengths have the different regularity of effects.


2019 ◽  
Vol 9 (9) ◽  
pp. 1049-1054
Author(s):  
Yunxia Lun ◽  
Fangfang Zheng

This study is aimed at exploring the effect of steel slag powder (SSP), fly ash (FA), and silica fume (SF) on the mechanical properties and durability of cement mortar. SSP, SF, and FA were used as partial replacement of the Ordinary Portland cement (OPC). It was showed that the compressive and bending strength of steel slag powder were slightly lower than that of OPC. An increase in the SSP content caused a decrease in strength. However, the growth rate of compressive strength of SSP2 (20% replacement by the weight of OPC) at the curing ages of 90 days was about 8% higher than that of OPC, and the durability of SSP2 was better than that of OPC. The combination of mineral admixtures improved the later strength, water impermeability, and sulfate resistance compared with OPC and SSP2. The compressive strength of SSPFA (SSP and SF) at 90 days reached 70.3 MPa. The results of X-ray diffraction patterns and scanning electron microscopy indicated that SSP played a synergistic role with FA or SF to improve the performance of cement mortar.


2021 ◽  
Vol 60 (1) ◽  
pp. 578-590
Author(s):  
Zhong Xu ◽  
Zhenpu Huang ◽  
Changjiang Liu ◽  
Xiaowei Deng ◽  
David Hui ◽  
...  

Abstract Geopolymer cementitious materials and recycled aggregate are typical representatives of material innovation research in the engineering field. In this study, we experimentally investigated a method to improve the performance of geopolymer-recycled aggregate concrete (GRAC). The recycled concrete aggregates and steel fiber (SF), fly ash (FA), metakaolin (MK), and sodium silicate solution were used as the main raw materials to prepare fiber-reinforced geopolymer-recycled aggregate concrete (FRGRAC). First, the orthogonal test was carried out to study the GRAC, and the optimal mix proportion was found. Second, building on the optimal mix proportion, the effects of the SF content on the slump, 7 and 28 days compressive strength, tensile strength, and flexural strength of FRGRAC were further studied. Finally, the microscopic mechanism of FRGRAC was studied by scanning electron microscopy (SEM). The study results indicate that the slump continues to decrease as the fiber content increases, but the compressive strength, tensile strength, and flexural strength increase to a certain extent. Through SEM analysis, it is found that SF restrains the development of cracks and improves the strength of concrete.


2020 ◽  
Vol 15 (1) ◽  
pp. 119-136 ◽  
Author(s):  
Muhammet Gökhan Altun ◽  
Meral Oltulu

ABSTRACT The use of recycled aggregate (RA) instead of natural aggregate (NA) in concrete is necessary for environmental protection and the effective utilization of resources. The addition of recycled aggregates in concrete increases shrinkage, porosity and decreases the mechanical properties compared to that of normal concrete. This study was aimed at investigating how the addition of various proportions of polypropylene and steel fiber affect the mechanical properties of recycled aggregate concrete (RAC). The natural coarse aggregates (NCAs) used in the production of normal concrete (NC) were replaced in 30% and 50% proportions by recycled coarse aggregates (RCAs) obtained from the demolished buildings. In this case, a polypropylene fiber (PF) content of 0.1% and steel fiber (SF) 1% and 2% volume fractions were used, along with hybrid fibers-a combination of the two. While the material performance of RAC compared to NC is analyzed by reviewing existing published literature, it is not evident what the use of RCAs and hybrid fibers have on the mechanical properties of concrete. The results showed that the compressive strength, flexural strength and impcat resistance of RAC were reduced as the percentage of RCAs increased. It was observed that the compressive strength was increased with the addition of 1% steel fiber in the RAC. The flexural and impact performance of steel fiber-reinforced concrete (Specimens NC and RAC) was increased as the volume fractions of steel fiber increased. The hybrid fiber reinforced concretes showed the best results in their mechanical performance of all the concrete groups.


2013 ◽  
Vol 341-342 ◽  
pp. 1458-1462
Author(s):  
Jian Gang Niu ◽  
Jian Bao ◽  
Yao Zhong Guo

In order to investigate the effect of fiber reinforced light-weight aggregate concrete on flexural tension properties, five groups of steel fiber reinforced light-weight aggregate concrete (SFLWAC) specimens with different steel fiber volumes including 0.5%,1.0%,1.5%,2.0%,2.5% and another five groups of plastics-steel fiber reinforced light-weight aggregate concrete (PSFLWAC) specimens with different plastics-steel fiber volumes including 0.5%,0.7%,0.9%,1.1%,1.3% were tested. The test results show that fiber can greatly improve ductility, and there are good interfacial bonding properties between fiber and light-weight aggregate concrete. The test results also show that it is not obvious to the upgrade of the flexural strength of light-weight aggregate concrete of LC30 with plastics-steel fiber. But the addition of steel fiber can gradually improve the breaking strength owing to the increase of steel fiber volumes.


Author(s):  
Xiaosa Yuan ◽  
Li Zhang ◽  
Xinxiao Chen ◽  
Fang Liu

Abstract To study the effects of graphene oxide (GO), fly ash, and steel fiber on the mechanical properties and durability of concrete, the mechanical properties, frost resistance, and internal pore structure of modified concrete are investigated by compression tests, freeze–thaw cycle tests, and industrial computed tomography (CT) tests. The test results show that the compressive strength of concrete with GO is better than that of mixed concrete, concrete mixed with only steel fiber, and ordinary concrete. Further, it is strongest at all ages when the GO content is 0.03%; the compressive strength of mixed concrete with 30% of fly ash is generally better than that with 15% and 45% of fly ash. In general, the frost resistance of concrete with only GO is better than that of ordinary concrete. With the increase in fly ash content, the internal porosity of concrete decreases, and its compressive strength increases accordingly; as GO increases, the porosity decreases and then increases, with the lowest porosity and the highest compressive strength of concrete at 0.03% of GO. With an increase in porosity, the mass loss and relative dynamic elastic modulus of concrete increase after 100 freeze–thaw cycles, which indicates that porosity directly affects the frost resistance of concrete.


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