Based on the results of this work a dosage of 0.5% by weight of dry soil using 7 mm fibers is optimal to improve crack control, flexural toughness and impact strength without statistically affecting flexural and compressive strengths.
However, a distinct trend showing improved cracking resistance of lightweight bridge decks was not noted for transverse cracking.
Overaging does not improve cracking resistance.
Currently, the state of the art is focused on the use of synthetic fibers in self-consolidating, fine-aggregate cementitious mixes that demonstrate strain hardening properties in tension, outstanding crack control and improved durability performance.
The mechanical properties and the crack control characteristics of concrete are significantly improved by the addition of steel fibres.
Steel fibers improves the durability and structural performance in terms of crack control and reduction of spalling and can replace shear reinforcement.
Continuing crack propagation existed after peak load due to the crack control effect of fibres on the cracked surface.
Fibers are used for improving some properties of conventional concrete (which is a brittle material) such as tensile strength, abrasion resistance, absorption and crack control.
Attempts at crack control are directed at reducing the width of each particular crack, in spite of the tradeoff of increasing the number of cracks.
So, crack control, crack width limitation and chloride threshold levels are well-established concepts in durability of reinforced concrete structures.
