Contribución al análisis y estudio de las posibilidades de variación de la cantidad de yeso, CaS04.2 H2O, como agresivo, del método acelerado de ensayo ASTM C 452 (1) (2) y (3). Parte IIB

Abstract

The reader should first refer to the summary of the IA(1), IB(2) and IIA(3) parts of this work (published in Materiales de Construcción nos. 209, 211 and 212, respectively) in order to have a clearer idea of the subject being dealt with herein. The use of the larger quantities of gypsum as aggressive agent than the 15.05% (≃ 7.0 % SO₃) specified by the ASTM C 452 method has shown its possible interest to users of cement and those who have to judge and/or recommend, or otherwise, its employment. In general the DEGREE OF RESPONSE of the parameter ΔL (%) in the case of the 21.0 % SO₃ and 14 days age test, continued by the 12.0% and 28 days age test, appear to be more appropiated to evaluate more precisely the Portland and pozzolanic cements which are tested thus. The 21.0% SO₃ content test has shown that not ALL THE POZZOLANIC CEMENTS have high or moderate sulphate resistance against seleniteuse water attack in contrast to the response shown by the rest of the cements with smaller SO₃ contents tested. It is recommended to carry out a appropriate, rational and representative investigation of pozzolanic cements to confirm, or otherwise, these last conclusion on those cements.