studied the effects of polypropylene fiber inclusion on the properties of alkali-activated cement mortars. The mechanical strength of plain and fiber-reinforced alkaline concretes was found higher than conventional ordinary Portland cement concrete with similar proportions of cement and fiber. studied mechanical behavior of pleated steel fiber incorporated AAS concrete. However, compressive strength of AAS concrete reduced with the fiber incorporation. As a result of their research, splitting tensile strength, flexural strengths and the properties related to durability performance were largely improved with the fiber addition. investigated the effects of steel fiber incorporation on mechanical and fracture toughness properties of concretes based on alkali-activated slag (AAS). However, there are few references concerning the influence of fibers on the mechanical properties of alkali-activated cements in the literature. In steel fiber reinforced concretes, the most important factors affecting the concrete properties are aspect ratio and dosages of fibers. The performance of fiber reinforced concrete depends on the properties of concrete and the fibers. According to their shape and quantity, fibers bear some of the stress that occur in the matrix themselves and transfer the other portion of stress to the stable cement matrix portions,. The extension and propagation of micro-cracks that occur due to the internal stresses in concrete are prevented by stress transfer capability of randomly distributed fibers.
#ALTERNATIVETO MINDLY CRACK#
The most important effect of fibers is prevention of crack propagation in concrete. Fiber inclusion is also an efficient method to improve shrinkage behavior of concrete. The inclusion of fibers in concrete or mortar substantially improves many of its engineering properties such as tensile strength, flexural strength, fracture toughness, resistance to fatigue, impact, wear, and thermal shock. Steel, glass, carbon, wood, synthetic and natural fibers are used for this purpose. This undesired behavior can be improved by inclusion of short discrete fibers into the matrix which prevent or control initiation, propagation, or coalescence of cracks.
Plain concrete is a brittle material with low tensile strength properties. During the past two decades, alkali-activated cements and concretes have attracted strong interest all over the world due to their advantages of low energy cost, high strength and good durability compared to Portland cements. Alkaline cements are comparatively new binders, alternative to the traditional Portland cements, obtained through the alkaline activation of different industrial by-products such as blast furnace slag and fly ash.
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