THE INDIRECT EFFECTS OF THE USE OF MINERAL ADDITIVES IN THE DURABILITY AND MICROSTRUCTURE OF CONCRETE PASTE, EXPOSED TO ABRASION

摘要

At the present, the use of mineral additives in the manufacture of concrete, has become a common and familiar practice for people who are involved in structure design of this type of additives. This condition in certain cases has favored the relaxation in the measured preventive in the use of this type of additive when this material is considered like raw material in the concrete's production. This paper reviews and analyzes the structure concrete case and as consequence of its exposition conditions and service and the use of an addition mineral inorganic type. It presented a premature deterioration. In the same one an analysis of the microstructure is presented and it permits certainly identify that is has been importantly affected by the inclusion in the concrete mixture of a specific component. The evaluation results and the employed criteria in the identification of the microstructure and their influence in the decrease of the durability are presented. In the present job, was reviewed and analyzed a concrete one, in which for it was employed an addition of inorganic material to give it a specific color. The concrete one was placed as a floor that served as a bearing surface in a workshop, where the service condition consisted in automotive vehicles and persons traffic. In a period lower than 6 months the material presented an important deterioration that consisted in a mortar paste superficial disintegration and a concrete delamination. The combination of characteristics, given a poor quality surface and a large porous volume spaces in the microstructure, is the main factor in the accelerated deterioration in the concrete structure, upon diminishing its resistance to the wear by abrasion. These two elements correspond to a group of deficiencies that they accelerate the abrasion surfaces just as is mentioned: Excessive manipulation of concrete, deficient cured and the air excess included with or without intention, where this type of deterioration is used to producing in floors surface and concrete hydraulic pavements, as a consequence of persons and vehicles traffic, and/or of its operation as area of maneuvers.