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This paper focuses on the effect of different types of stone powders as a partial replacement of coarse aggregate on the strength and porosity of pervious concrete. The used stones in this study were gathered from the foothill of Haibat–Sultan Mountain of Koya city located in Kurdistan region of Iraq. Four types of stones were used; mudstone, sandstone, marlstone, and limestone as 7% partial replacement of coarse aggregate. For all mixes, the same mix proportion of 1:4.5:0.4 by weight for cement, coarse aggregate, and water, respectively, was used. The test results have shown a noticeable decrease of porosity for all types of mixes, with an increase in the compressive and splitting tensile strength. The results displayed also the great role played by the fineness of stone filler in improving the strength of pervious concrete with acceptable porosity. Besides, they indicated that the sandstone and marlstone powders are effective filler in improving the strength of pervious concrete.

The effect of walnut shells on different properties of mortar was investigated through several experimental tests. The investigated properties include dry density, thermal conductivity, compressive and flexural strengths. Percentage replacements of the walnut shells to sand ratio were 5, 10, and 15%. The walnut shells used in this study were treated by soaking in boiling water for two periods: 1/2 hr and 1 hr. All mortar mixes have same proportion of 1:3:0.7 by weight for cement, sand, and water, respectively. The test results showed that the use of 15% walnut shells treated for 1/2 hr lead to decrease of the density and thermal conductivity of mortar by 15 and 31%, respectively. On the contrary, the compressive and flexural strengths of mortar were decreased by 17 and 25%, respectively, in comparison to the control mortar after 28 days of moist curing. This study leads to a conclusion that by soaking the walnut shells in boiling water for 1/2 hr enhanced the behavior of mortar compared to the un‐soaked ones. This results in achieving an acceptable strength, good thermal insulator, and environmentally friendly mortar.

The use of timber in the building industry has expanded in many countries over the last 20 years due mainly to its light weight, low adverse impact to the environment, and fair mechanical properties. Despite the development of the construction industry in the Kurdistan Region in Iraq (KRI) in recent years, timber product utilization is still very limited. Therefore, the purpose of this study was to investigate the feasibility of further utilizing timber-based products in the building industry in semi-arid regions using the KRI as a case study. A review of timber product utilization in the region was conducted first and the general properties of timber products were followed. Based on this, a survey focusing on the current situation and suitability of localized grown timber products was carried out to study the feasibility. This article concludes that the use of timber-based products in the KRI presents different barriers, with the availability in the market and technicality of construction with the material being the strongest ones. The article recommends that it is imperative to further research how to promote timber’s utilization in the KRI to be in line with sustainable development.

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A three meter-length cantilever beam loaded with a concentrated load at its free end is studied to determine shear stresses. In the present study, three cross sections are considered: rectangle (R); I, and T. The study presents a comparison of maximum shear stresses obtained by means of two methods: classical analytical equation derived by Collingnon, and finite element method (FEM) software. Software programs ANSYS and SAP2000 were used. The results show difference between the maximum shear stresses obtained by the analytical equation and the software, being the last is always higher. The average differences for ANSYS and SAP2000, independently of the cross section, were 12.76% and 11.96%, respectively. Considering these differences, correction factors were proposed to the classical analytical formula for each cross section case to obtain more realistic results. After the correction, the average differences decrease to 1.48% and 4.86%, regardless of the cross section shape.

The article presents the possibility of increasing the water-resistance of gypsum binders obtained based on synthetic gypsum by introducing additives derived from industrial wastes. Regularities were obtained for the influence of the type and amount of additives on the water-gypsum ratio, strength indicators, and water resistance of high-strength gypsum binder. The introduction of a single-component additive to improve water resistance does not have a significant effect. Complex additives based on Portland cement, granulated blast-furnace slag, electric steel-smelting slag, expanded clay dust and granite screenings of various fractions have been developed that make the maximum contribution to improving the water resistance of a high-strength gypsum binder based on synthetic calcium sulfate dihydrate, which made it possible to increase the water-resistance coefficient from 0.39 to 0.82.