USE OF CACTUS IN MORTARS AND CONCRETE

Natural polymers have been used in ancient times to improve the durabi lity of lime-based mortars and concretes. The natural polymers used we re locally available. In this work, cactus extract from Mexico has bee n tested in a Portland cement mortar. It is seen that cactus extract i ncreases the plasticity of the mortar and improves water absorption an d freeze-salt resistance. Calcium hydroxide produced by Portland cemen t hydration interacts with the components of cactus extract, polysacch arides or proteins, and forms complexes. It affects the crystallizatio n process. Painting of the concrete with this extract has also shown i mproved water resistance. (C) 1998 Elsevier Science Ltd.