Influence of glass fibers on mechanical and durability performance of concrete with recycled aggregates

Combined effects of supplementary cementitious materials (silica fume, GGBS, fly ash and rice husk ash) and steel fiber on the hardened properties of recycled aggregate concrete

In this paper, the partial replacement of volcanic pumice powder (VPP) was investigated for use as a supplementary cementitious material. High-strength concrete (HSC) was prepared using two sets of VPP (10% and 20%) incorporated with three sets of polypropylene fiber (PF) (0.20%, 0.35%, and 0.50%) to produce different concrete mixtures. Several tests, including slump, compressive strength, indirect tensile strength, flexural strength, water absorption, initial surface absorption, and sorptivity, were conducted to evaluate HSC performance. Results showed the prepared specimens with 10% cement replacement with VPP and 0.20% PF content indicated a slight increase in compressive strength compared with the control concrete at later ages. Indirect tensile and flexural strengths were optimized at 10% VPP replacement with 0.50% PF content. Furthermore, adding PFs to mixes increased indirect tensile and flexural strength but decreased slump. The sorptivity test indicated low water soaking due to VPP content in the mixes compared with the control mix (HSC); it declined as the replacement of VPP increased. The different standard tests on mixes depicted favorable results and good prospects for the inclusion of VPP in HSC structures.

Durability and strength characteristics of high-strength concrete incorporated with volcanic pumice powder and polypropylene fibers

This study aims to investigate the axial stress-strain behavior of macro-synthetic fiber reinforced recycled aggregate concrete. Concrete cylinders reinforced with macro-synthetic fibers were tested under axial compression, with the variation of three different replacement ratios of recycled aggregates (i.e., 0, 50 and 100%) and three different dosages of macro polypropylene fibers (i.e., 0, 0.5 and 1% of volume of recycled aggregate concrete). A comparative study of the existing stress-strain models for steel fiber reinforced normal and recycled aggregate concrete with the test results indicates that the stress-strain behavior of steel fiber reinforced normal and recycled aggregate concrete can be well predicted by these existing models. No stress-strain model for macro-synthetic fiber reinforced normal and recycled aggregate concrete has been developed. Based on the test results, a stress-strain model is developed in this work by modifying the parameters of best performing stress-strain model for steel fiber reinforced normal aggregate concrete. The proposed model can effectively predict the stress-strain behavior of both steel and macro-synthetic fiber reinforced normal and recycled aggregate concrete. Test results show that the peak stress, peak strain and ultimate strain of concrete specimens increase with the increase in fiber dosage and the addition of fibers has a better effect on recycled aggregate concrete and as compared to normal aggregate concrete.

Axial stress-strain behavior of macro-synthetic fiber reinforced recycled aggregate concrete

A step towards durable, ductile and sustainable concrete: Simultaneous incorporation of recycled aggregates, glass fiber and fly ash

Performance evaluation of polypropylene fibre reinforced recycled aggregate concrete

Use of silica particles to improve dispersion of -COOH CNTs/carbon fibers to produce HyFRCC

Development of low-carbon alkali-activated materials solely activated by flue gas residues (FGR) waste from incineration plants

Geopolymer coating modified with reduced graphene oxide for improving steel corrosion resistance

The present investigation is primarily aimed to study the effects of confinement of Glass fibre reinforced polymer (GFRP) and specimen size on the recycled aggregate concrete (RAC). The RAC is prepared by complete replacement of natural coarse aggregates (NCA) with recycled coarse aggregates (RCA). Strain gauges are used to study the variations of axial and lateral strain with axial stress. To examine the size effect the experimental investigation is carried out on specimen size of diameters 50, 100 and 150 mm with constant aspect ratio of two. A comparative study has also been drawn between NAC and RAC based on various parameters such as strength, effect of confinement on the stress-strain behaviour, effect of specimen size on strength and strain enhancement. Study reveals that there is effective load transfer from concrete to GFRP jacket resulting in improved strength in confined specimen. The size effect is more pronounced on strength enhancement of RAC compared to NAC for unconfined concrete. However, for confined concrete, pronounced size effect is observed in NAC over RAC on both strength and strain enhancement.

Chandra Sekhar Das

Papers

Performance evaluation of polypropylene fibre reinforced recycled aggregate concrete

Use of silica particles to improve dispersion of -COOH CNTs/carbon fibers to produce HyFRCC

Development of low-carbon alkali-activated materials solely activated by flue gas residues (FGR) waste from incineration plants

Geopolymer coating modified with reduced graphene oxide for improving steel corrosion resistance

Behaviour of confined recycled aggregate concrete under compressive loading: An experimental investigation