Crack-free concrete for outside industrial floors in the absence of wet curing and contraction joints

Estudio de la tecnología de concretos de contracción compensada aplicada a la construcción de pisos industriales

“…Luego de haber realizado pruebas experimentales y comparando los resultados con los expuestos por Collepardi et al (2008), quienes afirman que es posible realizar losas de grandes dimensiones usando un aditivo compensador de contracción ACC más otros aditivos super-plastificantes, sin realizar curado sumergido. Este tipo de procedimientos tendría un gran incremento en el precio del piso industrial ya que por el momento los aditivos son importados, lo que los hace costosos y comparado con otros métodos usados en la construcción de pisos industriales no sería viable.…”

The influence of expansive agent on the performance of fibre reinforced cement-based composites

“…A dead-burnt calcium oxide (CaO at about 99%) was used for FRCCs at a quite low dosage of 20 kg/m 3 (usually 30-50 kg/m 3 is the recommended dosage in order to use CaO as expansive agent [4][5][6][7]), while a higher dosage equal to 35 kg/m 3 was employed for UHPCs.…”

“…In fact, a problem involving these cement-based composites with low w/b ratio is the likely tendency to crack at early age, due to autogenous and plastic shrinkages. SRA proved to be effective in counteracting concrete cracking [18], but especially in combination with expansive agent it showed synergic effect [6][7][8][9]19].…”

“…However, Collepardi et al [6] found that there is a synergistic effect in the combined use of SRA and a CaO-based expansive agent in terms of more effective expansion, even in the absence of wet curing. In fact, due to the additional effect of SRA, shrinkage-compensating concrete was used to produce crack-free concrete without wet curing for an outside industrial floor of 800 m 2 in absence of contraction joints [7]. The synergistic effect of expansive and shrinkage reducing admixture was recently studied also by Meddah et al [8].…”

On the effect of the physical structure of cement on shrinkage of cementitious materials

“…Permeability reducing admixtures (PRA) [10], [11] and superabsorbent polymers [12], [13] have also shown promising results in terms of volume control and crack mitigation of concrete. There have also been studies on the effect of a combination of two or more types of chemical admixtures to make crack-free concrete [14]. However, in spite of the fact that the addition chemical admixtures can help to alleviate cracking in concrete, less attention has been paid to the physical structure of cement as a measure to control both hydration kinetics and pore structure in order to prevent tensile stresses induced by cement hydration just from the beginning.…”