Experimental study on the basic phenomena of shrinkage and cracking of fresh mortar

摘要: Abstract Evaporation, horizontal shrinkage, settlement, setting and capillary pressure of mortar mixes were measured during first hours with samples which exposured to wind (velocity 4 m/s, T = 20 °C RH 40%). The effects different admixtures (super plasticizer, accelerating, retarding, air-entraining agent one type fibre) on the shrinking behaviour mortars studied accordingly. well-known fact that proper long-term wet curing is vital for crack-free surfaces concrete or was confirmed experimentally. beginning can be regarded as a critical moment. After has capacity resist forces thus shrinkage. mix modified by super plasticizer behaved unexpectedly, surface sample cracked. This cracking indicated zig-zag in shrinkage pressure. Air- entraining reduced considerably. Use fibre about 30% when compared without fibre. Based results some conclusions are drawn concerning properly limed trowelling