Gypsum-cement reactive powder concrete

Building Materials

Current state of construction science causes for the repair and strengthening of unique buildings and structures using binders and concretes based on them having a high strength and speed of her set, which includes the so-called reactive powder concrete - Reactive powder concretes (RPC). However, most of these concretes currently received broad scientific and practical development, based on Portland cement hydration rate is limited and, obviously, today has reached its limit. This makes it impossible to accelerate work on the repair and strengthening of unique buildings and structures. Relevance of the work is the need to obtain and study RPC, with high speed curing, high compatibility with concrete structures and other properties of a sufficient level of performance. It is known that a sufficiently high rate of setting and hardening of gypsum binders have, however, they have a reduced water resistance, which restricts their area of application. Increase the water resistance of gypsum can be achieved by coadministration of gypsum binder in Portland cement and hydraulic additives - give gypsum cement binder. According to the composition of its components on gypsum cement concrete binder can be attributed to the RPC, which have a high rate of setting and hardening, as well as compatible with concretes existing constructions. Consequently they have no disadvantages inherent in other known species of RPC. The aim is to investigate the possibility of obtaining and properties of RPC-based gypsum cement binder. Thisgoal is achieved by using in the preparation of gypsum cement as hydraulic binder in finely divided additives soda lime silicate glass by mixing the dry ingredients with an aqueous solution of a polyalcohol. The resulting particulate reaction gypsum cement concrete has a compressive strength reaching 35 MPa, coefficient of the water resistance of not less than 0.9 at high speed curing.