Strengths and Failure Characteristics of Self-Compacting Concrete Containing Recycled Waste Glass Aggregate

The effects of different proportions of green-colored waste glass (WG) cullet on the mechanical and fracture properties of self-compacting concrete (SCC) were experimentally investigated. Waste bottles were collected, washed, crushed, and sieved to prepare the cullet used in this study. Cullet was incorporated at different percentages (0%, 20%, 40%, 60%, 80%, and 100% by weight) instead of natural fine aggregate (NFA) and/or natural coarse aggregate (NCA). Three SCC series were designed with a constant slump flow of 700±30 mm, total binder content of 570 kg/m3 and at water-to-binder (w/b) ratio of 0.35. Moreover, fly ash (FA) was used in concrete mixtures at 20% of total binder content. Mechanical aspects such as compressive, splitting tensile, and net flexural strengths and modulus of elasticity of SCC were investigated and experimentally computed at 28 days of age. Moreover, failure characteristics of the concretes were also monitored via three-point bending test on the notched beams. The findings revealed that the mechanical properties as well as fracture parameters were adversely influenced by incorporating of WG cullet. However, highest reduction of compressive strength did not exceed 43% recorded at 100% WG replacement level. Concretes containing WG showed less brittle behavior than reference concrete at any content

Effect of mineral admixture on the properties of engineered cementitious composite

Engineered cementitious composites are a new kind of fiber-reinforced cementitious composite that exhibits superior performance. They may be used to reduce maintenance and repair costs, extend the service life of buildings, and overcome ordinary concrete's lack of bendability. The purpose of this study was to determine the effect of replacing cement with up to 10% silica fume on the characteristics of Engineered Cementitious Composites concrete with a binder concentration of 1000 kg/m3 and two kinds of fiber (steel and carbon). Numerous experiments were conducted to determine the behavior of Engineered Cementitious Composites concrete, including compressive strength for (cubes and cylinders), tensile strength for splitting, flexural strength, and load-bearing capacity (when slabs at simply supported and fixed). The experimental findings indicated that up to 10% substitution of silica fume for cement increased the compressive strength of this kind of concrete after 28 days. Other parameters such as splitting tensile strength, flexural strength, and load-bearing capacity exhibited the similar pattern

Rheology and Permeability of Self-Compacting Concretes with Recycled Blue Aggregate

Since the sustainability of concrete became a very important property in the past decades, 15 mixes of self-compacting concrete (SCC), as well as control mixes, were examined to find out the effect of replacing natural aggregates with recycled blue glass (RBG) waste on the rheological properties and permeability of self-compacting concrete. For this purpose, 3 series of SCCs were mixed: the 1st group replaced the natural aggregate (NFA) with fine recycled waste blue glass (RFWBG), the 2nd group replaced the natural coarse aggregate (NCA) with coarse recycled waste blue glass (RCWBG), and the last group replaced the natural aggregate with recycled blue glass (RGA). Each group contains 5 ratios of replacement (0%, 20%, 40%, 60%, 80%, and 100%). The results showed that the torque increased with the increase in recycled green glass replacement; for instance, it increased from 0.95 for control mixes to 1.302, 1.384, and 1.459 Nm for 100% replacement in the 1st, 2nd, and 3rd groups. Meanwhile, the permeability tests include chloride ion permeability (RCPT), a water sorptivity test, and a gas permeability test at 28 days; likewise, this study showed that these characteristics increase with the increase of recycled blue glass