Hydraulic-lime based concrete: Strength development using a pozzolanic addition and different curing conditions

Concrete is a major worldwide building material, in which Portland cement is the usual binder. Taking into account environmental factors in cement production, especially concerning CO2 emissions and energy consumption, this work aims at the development of concrete with a hydraulic-lime binder; in order to increase mechanical strength, pozzolanic materials were added. In this preliminary study, compositions with different percentages of hydraulic lime were tested and a pozzolanic material, a residue from expanded clay production, was used. Variations in percentage of pozzolan and conditioning were carried out. Concrete specimens were tested for mechanical strength at various ages and a pozzolanic index was determined in order to evaluate the influence of the pozzolanic material on attained mechanical strength. This paper presents the results of this testing campaign, concluding on the influence of pozzolanic additions and curing conditions on the strength development of this material.