The impact resistance and mechanical properties of reinforced self-compacting concrete with recycled glass fibre reinforced polymers

Use of silica fume and recycled steel fibers in self-compacting concrete (SCC)

Engineered Cementitious Composites (ECC) have demonstrated superior mechanical and durability performance than conventional concrete. In the micromechanical reinforcing system of ECC, fibers play a pivotal role in establishing the ultrahigh tensile ductility and autogenous crack width control. This article reviews the state-of-the-art of discontinuous micro-fibers as intrinsic reinforcement of ECC regarding technical performance as well as environmental and economic impacts. Mechanical properties of ECC made with different micro-fibers, man-made or natural, and their embodied energy, emissions and material cost, are comprehensively surveyed. Further, studies on fiber hybridization are discussed regarding the combination of different types of fibers to form synergetic reinforcements that mitigate total material cost, and potentially enhance the composite performance. Recommendations on fiber selections are highlighted and directions for future research are suggested.

Discontinuous micro-fibers as intrinsic reinforcement for ductile Engineered Cementitious Composites (ECC)

Development of fly ash/slag based self-compacting geopolymer concrete using nano-silica and steel fiber

An experimental work was carried out to investigate the effects of micro-steel, hooked-steel, and micro-glass fibers on the mechanical properties and ductility of Ultra-high Performance Cementitious Composites (UHPC). The aspect ratios of the of micro-steel, hooked-steel, and micro-glass fibers were 7.17, 55 and 722, respectively. At a water-binder ratio of 0.195, three groups of UHPCs containing 0.25, 0.5, 0.75, 1, 1.5, and 2% fiber volume fractions were produced and tested for compressive strength, splitting tensile strength, modulus of elasticity, flexural strength, load-displacement behavior, fracture energy, and characteristic length. Test results revealed that the mixes with 2% of micro steel fiber exhibited the best compressive strength of 180 MPa as well as the highest splitting tensile strength and modulus of elasticity. However, the mixes with 2% of hooked steel fiber displayed a strain hardening load-displacement behavior with a substantially enhanced ductility. The results also showed that the beneficial influence of using micro glass fiber began to decrease after 1.5% of the fiber volume.

Strain hardening ultra-high performance fiber reinforced cementitious composites: Effect of fiber type and concentration

Mechanical properties of steel fiber reinforced high strength lightweight self-compacting concrete (SHLSCC)

Risk management is an important field of construction industry and has gained more importance internationally due to the latest researches carried out on a large scale. However, this relatively new field requires more attention to bring some benefit. Construction projects are facing a number of risks which have negative effects on project objects such as time, cost and quality. This study is based on findings of a questionnaire-based survey on risk management in construction projects in Pakistan, reporting the significance of different type of risk, ultimate responsibility for them and the effectiveness of some most common risk management techniques practiced in the industry. Two types of risk management techniques were considered: preventive techniques which can be used before the start of a project to manage risks that are anticipated during the project execution; and remedial techniques that are used during the execution phase once a risk has already occurred. The study revealed that financial ...

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Risk management in construction projects

Combined influence of glass powder and granular steel slag on fresh and mechanical properties of self-compacting concrete

Concrete is weak in tension and fibers are added to it to make it ductile. One of the commonly used methods, for this purpose, is the addition of steel fibers of different geometries. However, failure of fiber reinforced concrete is initiated by pulling out of fibers, failing to utilize their full capacity. In this study, closed steel fibers (CSF) are proposed for addition into concrete. The objective was to avoid the pulling out of fibers in tension for full capacity utilization. When CSF are embedded into concrete, they are expected to reach the breaking point, utilizing their maximum capacity due to the presence of concrete matrix within the closed geometry of fibers. Different volumes of straight steel fibers (SSF) and CSF were used to investigate and compare their performance. Fresh and hardened concrete properties were considered. Results indicated decrease in workability of fiber reinforced concrete with increasing steel fiber content. No significant change in concrete compressive strength and modulus of elasticity was noted. There was a maximum of 46% increase in tensile strength while 36% increase in flexural strength of concrete with the use of CSF compared to that of SSF. The failure of concrete in tension was initiated by pulling out of open fibers and breaking of closed fibers. Thus, use of closed steel fibers is recommended to make full use of steel fiber tensile capacities which may revolutionize the field of fiber reinforced concrete.

Ahsan Ali

Papers

Mechanical properties of steel fiber reinforced high strength lightweight self-compacting concrete (SHLSCC)

Risk management in construction projects

Combined influence of glass powder and granular steel slag on fresh and mechanical properties of self-compacting concrete

Enhanced mechanical properties of fiber reinforced concrete using closed steel fibers

Effect of Change in Micro Steel Fiber Content on Properties of High Strength Steel Fiber Reinforced Lightweight Self-Compacting Concrete (HSLSCC)