Curling in concrete floors - Causes and repair

Many industrial floors are required to have high quality flat surfaces for the operation of specialised equipment, particularly high-reach stackers operating from warehouse floors. For new floors, the essence of floor flatness lies in the manner of finishing and the regular monitoring of the flatness achieved. Achieving such surfaces however, is quite difficult because of the high drying shrinkage in flat slabs that cause them to curl at the joints. Curling at the joints, seriously affects the operation of an industrial facility. Floors subjected to heavily-loaded forklift traffic rapidly deteriorate causing safety problems. Curling is also augmented in industrial floors by the use of power trowelled surface hardeners to produce the dense high-strength top surface required for high wear resistance. Repair of curled floors in industrial locations involves grinding, patching, installation of dowels and grouting underneath the curled slab. The timing and appropriateness of the method used are of vital importance to the durability of the repair. Aspects of design and construction to avoid curling of new industrial floors; the factors that contribute to cracking and curling; measures to minimise curling and the repair of curled floors are discussed in, this paper.