No abstract

No abstract

No abstract

This paper aims to evaluate the impact of ceramic waste powder (CWP), micro silica (MS) and steel fiber (SF) on self-compacting mortar. CWP at ratios of 10 and 20%, and MS at 1 and 5% by weight of cement were replaced the cement. Beside, SF was added at ratios of 0.5 and 1% of cement. Mini slump flow diameter and mini V-funnel flow time tests were carried out to determine the workability of fresh composites. Compressive strength, flexural strength, water absorption, electrical resistivity and drying shrinkage tests were performed on hardened mortars. Scanning electron microscope (SEM) technique was employed to assess the microstructure. The results indicated that CWP reduced the mechanical properties by about 20% and increased permeability by about 14%. However, inclusion of micro silica particles improved the properties outstandingly. Compressive strength increased about 30% by inclusion of MS. It was also observed that the addition of fibers from 0.5% to 1% increased the flexural strength. This improvement was more obvious in samples with higher contents of micro silica. It can be reported that by including the both micro silica and steel fibers, the bonding between the cement paste and fibers was developed. Replacement of micro silica led to increase of electrical resistivity by about 99% in samples containing 20% ceramic waste powder. The microstructure studies confirmed the significant increase of density and uniformity of the hydration products in the presence of micro silica particles.

Impact resistance of Portland cement concrete (PCC) is an essential property in various applications of PCC, such as industrial floors, hydraulic structures, and explosion-proof structures. Steel-fiber-fortified high-strength concrete testing was completed using a drop-weight impact assessment for impact strength. One mix was used to manufacture 320 concrete disc specimens cured in both humid and dry conditions. In addition, 30 cubic and 30 cylindrical specimens were used to evaluate the compressive and indirect tensile strengths. Steel fibers with hooked ends of lengths of 20, 30, and 50 mm were used in the concrete mixtures. Data on material strength were collected from impact testing, including the number of post-first-crack blows (INPBs), first-crack strength, and failure strength. Findings from the results concluded that all the steel fibers improved the mechanical properties of concrete. However, hooked steel fibers were more effective than crimped steel fibers in increasing impact strength, even with a smaller length-to-diameter ratio. Concrete samples containing hybrid fibers (hooked + crimped) also had lower compressive strength than the other fibers. Comparisons and analogies drawn between the test results and the static analyses (Kolmogorov–Smirnov and Kruskal–Wallis) show that the p-value of the analyses indicates a more normal distribution for curing in a humid environment. A significant difference was also observed between the energy absorptions of the reinforced mixtures into steel fibers.

No abstract

No abstract

No abstract