Estudo da reação pozolana artificial e cal: influência do tipo de pozolana, tempo de cura, temperatura de reação e temperatura de calcinação sobre a resistência mecânica das argamassas.

Abstract

The knowledge of the materials used in civil construction is of great importance due to the complexity of obtaining better mechanical properties and hence to optimize them. Now a days, the pozzolanic incorporated in Portland cement are gaining increasing importance as they reduce the energy consumption as well as in obtaining products with technological characteristics even better than simple cement itself in some aspects. The thermal activation of clays is one of the most important option for producing pozzolan due to greater existence of the clay deposits in our country. The kaolinite clays are considered to be more appropriate for the production of pozzolan, which are found in the north-east of Brazil and hence some of researchers of the region investigate these clays. The present work had objectives to study pozzolan-lime reaction with reference to the influence of factors like type of pozzolan, curing temperature, temperature of reaction and temperature of calcination on the development of the compressive strength of the mortars. In order to evaluate the mechanical performance of the mortars test specimens, of cylindrical shape with 5 cm x 10 cm size where prepared. The agglomerated was composed of 60% lime and 40% pozzolan, cured in air and controlled atmosphere with approximate 100% relative humidity. The proportion of agglomerate and sand was kept 1:2.5 by weight respectively. The factor of water to agglomerate plus sand was taken 0,48. It is observed that the compressive strength was higher when the pozzolan used in the mortar was of smaller particles, it increased with the curing temperature, with the reaction temperature, with the reaction temperature and the calcination temperature.