Concrete water-proofing

Abstract

This article refers to concrete water-proofing, and the different sealing systems used. After a brief study of the different types of pores and air and water capillaries, the various kinds of water penetration —penetrability and hygroscopicity— are analyzed. The origin of the water is studied: natural moisture, construction humidity, moisture coming from absorption and condensation, rain, accumulated water pressure and miscellaneous moisture and the damaging effects they have on permeability and on hygroscopicity; losses in reservoirs, sub-pressure, Chemical reactions and oxidation. The different forms of measuring permeability are also studied: DIN Standard, by means of test tubes in the form of plates; ASTM Standard, by freezing and permeability tests, by means of a permeability meter, etc. After analyzing the basic conditions for decreasing water penetration in the concrete the following is considered. a) Means of additives or treatments which improve the quality of same in order to obtain optimum conditions for waterproofing; b) using products which avoid water penetration inside the concrete mass, without altering its basic properti.es. These two forms refer to different waterproofing systems: mass, hydrofugous, joints, sheets and continuous lining. These systems are studied in detail as far as their effects, characteristics and applications are concerned.