Research about the Capillary Absorption of Concretes with Cuban Limestone Aggregates

摘要

More than the 98 % of the aggregates used in Cuba have a limestone origin, with absorption values more than 1% in the majority of the cases, and with a high porosity too. On the other hand the tests of capillary absorption by G?ran Fagerlund method, over concrete cores taken from several real structures submitted to very aggressive marine environments, have shown porosity values higher than the indicated by the DURAR Latin Working Group. A research was developed by the Technical University (Cujae) and the Center of Construction Researching (CTDMC) of Havana, that showed us the possibility to obtain in Cuba concretes with values of effective porosity lower than 10% with w/c ratios of 0,4 and 0,45 if the normative requirements established in Cuban Normative about the concrete minimum curing time and a full consolidation are fulfilled. However the absorption speed values (Sorptivity) with the same Cuban Standard NC 345, were not fulfilled in any cases the requirements established by the DURAR Latin Working Group. A more specific and complete research about the trial method proposed by the ASTM C 1585 (Sorptivity test, which have different specifications about the preparation of the samples) was recommended to compare its values with the requirements proposed by the DURAR Latin Working Group.