No abstract

Sawdust waste material is a by-product of manufacturing furniture and other wood products. It poses a major problem for the environment if no action is considered to get rid of it. For this reason, this research presents a new modality for recycling sawdust west material as a partial replacement of a plaster of Paris (POP). Six composite mortars prepared from different sawdust ratios 0, 2, 4, 6, 8 and 10 % by wt. of POP were used to investigate the physical and mechanical properties of these mortars. The effect of different temperature levels (100, 200, 300, 400 and 500 Cₒ) on the properties of these composite mortars was also investigated. The results show that the optimal proportion of sawdust in the mortar was 10 %, where the compressive strength increased by about 51.47 % compared to the reference mix (without sawdust) at 50 Cₒ. Additionally, there was a development in the modulus of rupture (MOR) for composite mixtures. The 6% sawdust content exhibited a 28.33 % increase in MOR. It was also found that sawdust reduced the density of the samples. Raising the temperature to 200 Cₒ and beyond affects the mechanical properties negatively.

Pistachio shells (PS) are one of the agricultural wastes, that are considered as economic and wide available material. It has some features that encourage using it to produce lightweight concrete and cement mortar. The essential objective of the current investigation is to evaluate the possibility of incorporating PS as a fibre in the cement mortar and the effect on its properties. Four different fibre percentages (0%, 0.5%, 1% and 1.5% by volume of cement) were examined. After curing the samples for 7 and 28 days, the fundamental properties of the cement mortars, including splitting tensile and compressive strengths I addition to the density, were determined and compared. The results revealed that the optimum content of the pistachio shells fibre lies between 0.5% and 1% where the splitting tensile and compressive strengths increased and the mortar’s density reduced at age of 28 days.

No-fines concrete is a distinctive kind of concrete that has an amount of porosity that lets the water and any liquid sources pass immediately through it. Often, many mechanical properties of concrete refer to its strength through the testing of the compressive strength, flexural strength, and splitting tensile. Thus, this research mainly focused on the splitting tensile strength with different mix ingredients. Two series of penetrable concrete were prepared to study the effect of two parameters on such concrete. In the first group, the sand was eliminated for one sample and the styrene butadiene rubber (SBR) was added to the mix with a percentage of 5% and 8% by cement weight. The second group was to study the effect of a partial replacement of coarse aggregate with sand in three varied proportions of 15%, 30%, and 45% of the total volume of aggregate. The water/cement ratio (w/c) was chosen to be 0.38 and 0.42. The results showed that the sand content has a higher positive effect than SBR on the tensile strength of pervious concrete.