DRY MIXTURES

[:ru]Шеин А. Л.[:en]Shein A. L.[:] [:ru]канд. техн. наук, директор по качеству, ООО «Строймонтаж МС», Россия[:en]Cand. Eng. Sc., Quality Assurance Director, LLC «Stroymontazh MS», Russia[:]

[:ru]Голованов С. В.[:en]Golovanov S. V.[:] [:ru]инженер-технолог, ООО «Строймонтаж МС», Россия[:en]Engineer-Technologyst, LLC «Stroymontazh MS», Russia[:]

Alitinform №2 (14) 2010 г. 78-87 p.

Abstract

In the second half of the 20th century, there arose a necessity for improvement of industrial floor coverings which would be capable of withstanding heavy loads, as well as numerous negative impacts. Concrete has always been the main and inexpensive material for industrial floors. As known, concrete resists compression well, but flexural loads — poorly. Among disadvantages that are the most apparent in a process of concrete floors exploitation is a low surface strength, which is a reason for concrete dusting. This is exactly, what is to be avoided by builders when creating industrial concrete floor coverings. Traditionally, ironing, i. e. rubbing cement onto cement mortar being set, was used with a purpose to strengthen the concrete surface. During this process, water-cement ratio was reduced in the surface layer, density and strength were increased, probability of concrete mix stratification, and dusting, were reduced. However, the problem was not solved completely; excessive amount of cement in a thin surface layer increased shrinkage, which caused cracking, and separation of a surface layer. The need arose for new materials, which are to be inexpensive and firm, compatible with concrete by a type of a binding agent, and a setting pattern, as well able to eliminate dusting and increase longevity of concrete. Finally, such materials had been created (Fig. 1). They were first invented in the USA, then in Europe. Now, they are used all over the world. These are so called «toppings» (from engl. topping — 1) upper layer of concrete cover, floor, road, wearing layer; 2) application of upper protective or covering layer; 3) concrete surface rubbing).