This study focuses on the reuse of waste ferrochrome (FeCr) slag as a partial replacement for sand in the production of cement mortar with improved thermal and mechanical properties. Sand was replaced by FeCr slag in different percentages ranging from 0 up to 20% (by weight). The flowability test was performed to evaluate the mortar’s behavior in a fresh state. Tests for the compressive strength, flexural strength, drying shrinkage, thermal conductivity, and specific heat of the blended mortars have been conducted according to ASTM standards at 3, 7, and 28 days of curing. X-ray diffraction (XRD) was utilized to examine the phase composition. The scanning electron microscope (SEM) was used for inspecting the microstructure changes of the hardened samples. The results revealed considerable improvements in the compressive and flexural strengths; improvement ratios of about 33 and 39% were attained respectively at 20% FeCr slag replacement after 28 days of curing. The drying shrinkage generally decreased with increasing replacement of sand by FeCr slag. FeCr slag acts to increase both the thermal conductivity and specific heat effectively. FeCr slag caused remarkable modifications in the microstructure of the blended mortars.

This paper reports a laboratory study investigating the use of granulated copper slag as a fine aggregate in hot-mix asphalt concrete. Marshall-mix design was performed on different blends of aggregate containing up to 40% copper slag. The dynamic modulus |E*| test, as a primary material property input in the Mechanistic-Empirical Pavement Design Guide (ME-PDG), was conducted at different frequencies (0.1 to 16 Hz) and temperatures (25 to 60°C). |E*| master curves and shift factors were developed for the control and slag mixes. The developed curves were compared with the Witczak predictive |E*| model for Levels 2 and 3 of the ME-PDG. The results indicated strength reduction as slag content increases in the mixes compared to the control mix. The developed master curves and shift factors were compared with the Witczak predictive model. The results of stripping potential evaluated by the indirect tensile strength indicated a reduction in strength, but the tensile-strength ratio was superior to that of the co...

This paper presents the results of an investigation to study the possibility of developing concrete blocks using waste materials. The blocks were produced from three waste materials: vermiculite and polystyrene beads, which were used as lightweight aggregates with different proportions in the mix, and cement kiln dust (CKD), which was used as a partial replacement for cement. The strength of the three types of blocks and the strength of masonry columns constructed from the blocks were compared with another two types of normal weight concrete blocks with and without high thermal insulation properties. The thermal insulation property of the developed lightweight concrete blocks was also compared. Results showed that lightweight concrete blocks manufactured from polystyrene had lower thermal conductivity than vermiculite and ordinary concrete blocks despite the variation in the density and compressive strength, and that the addition of up to 15% CKD as a cement replacement has a negligible effect on the stre...