Strength Performance of Free Cement Mortars Incorporating Fly ASH and Slag: Effects of Alkaline Activator Solution Dosage

In recent days, the reduce of carbon dioxide emission, cost and energy consumption are the main concern in urban countries worldwide. Concrete is the main construction materials and the Ordinary Portland Cement (OPC)is primary binder in concrete industry. OPC industry cases many environmental problems such as carbon dioxide emission and high energy consumption. Alkali-activated paste, mortars and concrete are introduced as alternative materials to OPC in concrete production with lower energy consumption and carbon dioxide emission. In the experimental, the alkaline activator solution effects on fresh and hardened properties of binary blended alkali-activated mortars were evaluated. The wastes materials such as fly ash (FA) and ground blast furnace slag (GBFS) were incorporating with river sand to prepare the mortar specimens. To activate the blend, six dosage of alkaline activator solution were used for this purpose. The results of tested specimens shown the enhancement in flowabiliry of mortar with increasing content of alkaline solution. The highest strength was achieved with specimens’ mortar prepared with ratio 0.40 of alkaline solution to binder content at 28 days of age. For all prepared alkali-activated mortar’ specimens, a good direct relationship was found between the flexural, splitting tensile and compressive strength.