Industrial Processing Technique for Textile Reinforced Cement Composites with Structural Use

摘要

The post-cracking hardening behavior under tensile loading of high performance fiber reinforced cement composites is determined as well by the fiber volume fraction as by the reinforcement structure and its impregnation by the matrix. High volume fractions can be obtained by using a continuous fiber structure in textile form, as is usual for polymer matrix composites. The corresponding processing techniques should thus be similar to polymer matrix composite manufacturing. However, due to the presence of an important powder fraction in the matrix raw material mix, the impregnation of the fiber structure as a whole or on the level of fiber bundles, is difficult. The impregnation process has to be considered as an independent processing step. A new device, called Self Compacting Impregnator (SCI) has been developed. It consists of two parallel grooved cylinders rotating in opposite sense, which squeeze the cement matrix in and through the textile fiber structure by applying a controllable pressure, thus enabling the continuous industrial production of well impregnated textiles, which can be processed and shaped further. Fiber volume fractions of more than 20% can be obtained. Test plates were manufactured by careful hand lay-up as reference, and by SCI impregnation as comparison. Mechanical testing (static tensile strength and fatigue loading) indicate that the proposed processing technique yields superior results to hand lay-up.