Properties of concretionary laterite gravel concrete

The compressive strength and the expansion of conrete made with both highly and slightly/moderately indurated concretionary laterite gravels were studied. The compressive strength (19–42 MPa) of most of the laterite concrete is comparable with the average strength (45 MPa) of concrete made with the usual granite crushed rock aggregates from the region. The strength of the laterite concrete is mainly dependent on the aggregate-cement bond whereas the physical properties of the aggregates are only of secondary importance. The laterite concrete showed a net contraction when immersed inhot 1N NaOH solution (i.e. rapid alkali reactivity test). This behaviour is attributed to the low/very low contents of silica, clay and lime in the aggregates. The results of the study reveal that concretionary laterite gravels are potential alternative cheap sources of aggregates for structural concrete.