BENTONITE AS AN ADDITIONAL MATERIALS IN R. CSTJ UCTURES

Abstract

Bentonite is a natural material. It has been found in most mountains of Egypt. Bentonite is produced from a clear clay. From several years old, bentonite was been imported but bentonite now produce in Egypt. Bentonite consists of different groups of oxides with different percents of according to international specification of bentonite (A.P.I & OCMA) [1 & 28].

Bentonite have many uses at this moment. Bentonite is used in (i) Building materials (as rendering & painting) for the sun-dried bricks, (ii) in grouting the earth [20 &23], (iii) excavation of key trenches with high depths (as piles or continuous panels) [20 & 23], (iv) in (temporary & mainly) diaphragm walls to prevent the failure of earth or to be permanent with high effective than the previous types (steel sheets or woods) [20, 25 & 33], (v) stent walls (as watertight sheets) which used for construct many projects to prevent permeability of water [20 & 25] and (VI) bentonite also added to water mixing for concrete mixes to prevent a corrosion of steel in reinforced concrete mixes [12].

Therefore we eager to know what is the suitable present of bentonite to concrete mixes and it's effect on physical and mechanical properties of concrete specially it's resistance against permeability of water.

In this study, the suitable percent of bentonite as (slurry and powder) and it's affect on physical & mechanical properties of concrete mixes (fresh and hardened) are presented. Comparison between the suitable percent of bentonite (as slurry) and alternative dose of admixtures and it's additional coasts of additives is reported.