|Crack-free concrete is defined as a mixture of concrete with anti-cracking properties. Crack-free concrete can be manufactured by using an expansive agent with adequate wet-curing requirement. Wet-curing is carried out after demolding. A surface treatment should be wet-cured for at least one week. Generally, crack-free concrete is ideal to be used for outside industrial floors, without using the contractor joints and in the absence of any wet-curing. Typical reinforcement of concrete is provided at the macro and micro scales by using macro and micro fibers respectively.
Factors such as increasing investments in the building & construction sector and rising demand for crack-resistant concrete structures are driving the crack-free concrete market. On the other hand, drawbacks associated with incorporation of CNTs (carbon nanotubes) in cement-based materials are hampering the crack-free concrete market. Also, lack of uniform dispersion of CNTs within the matrix and high initial cost of incorporating CNTs are hindering the crack-free concrete market.
In terms of type, the crack-free concrete market has been segmented into conventional aggregate, lightweight aggregate, and others. Lightweight aggregate includes pumice, scoria, and tuff. Most lightweight aggregates are prepared by the U.S.-based companies. The others segment comprises sintered fly ash, expanded slag, and bed ash.
In terms of mix design, the crack-free concrete market has been divided into shrinkage-reducing admixtures and shrinkage-compensating cement. The latter is less expensive than the former.
Based on reinforcement, the crack-free concrete market has been bifurcated into cement paste reinforced with CNTs (carbon nanotubes) and cement paste reinforced with CNFs (carbon nanofibers). The nanofibers added not only improve fracture properties of the cement matrix by controlling matrix cracks at the nanoscale level, but also enhance the early-age strain capacity of the cement matrix, producing high-performance nanocomposites.