The effect of moisture content on the compressive strength of hollow concrete blocks

Abstract

The purpose of this dissertation was to examine to what extent the moisture content of a hollow concrete block affects its compressive strength. In addition, the applicability of the Euronorm standards to the Maltese context was also investigated. The difference in compressive strength resulting from different degrees of moisture content was analysed through the following quantitative study. A total of 42 hollow concrete blocks were tested. The specimens were split into 7 sets (6 hollow concrete blocks per set) of varying moisture content. Each set was conditioned accordingly until the moisture content needed was reached and then tested in compression. The main findings from the research carried out was that, in general, the compressive strength for hollow concrete blocks decreased as the moisture content increased. The exception was that the samples conditioned at 6% moisture content reached an overall compressive strength greater than that of the ones tested at 0% moisture content. In addition to this, it was found that the 6% moisture content assumed to be equivalent to the air-dry condition does not stand for the Maltese context. The moisture content within the air-dried blocks were found to be much higher. In conclusion, this study successfully exhibits the change in compressive strength of hollow concrete blocks when the moisture content is increased to various levels between 0% and 100% moisture content. It also provides valuable insight into the applicability of the standards used within the local context to the Maltese climate.