Shrinkage of extruded fiber reinforced cement mortar board

The shrinkage of extruded fiber reinforced cement mortar board was investigated experimentally as a function of the cement and fiber types, water to cement ratio, and fiber content. The shrinkage was significantly reduced by using a low-shrinkage composite cement in the matrix with a shrinkage strain at 50 d of only half that of normal Portland cement board. In addition, the development of the shrinkage with time was faster for the low-shrinkage composite cement board than for the normal Portland cement board. The volume of the low-shrinkage composite cement board becomes stable in only 5 to 10 d after casting while the shrinkage of the normal Portland cement board kept increasing for at least 50 d. The fiber type was found to have little effect on the shrinkage with the addition of fibers increasing the shrinkage a small amount.