Accelerated Mix Design of Lime Stabilized Materials

Abstract

Increasingly it is necessary to search for alternative materials to the construction industry to turn it more sustainable. In this regard, fly ash and carbide lime—residues from production processes—are targets of this study because of their applicability in the stabilization of slopes, base of pavements and manufacture of artifacts for building construction. Therefore, this work aims at the development of method (technique) that enables the prediction of the compressive strength for long curing time periods at standard laboratory curing temperature (23°C) through prediction equivalence with accelerated curing (using temperatures of 40 and 60°C). The porosity/carbide lime (η/Lv) ratio (corresponding to porosity divided by the volumetric carbide lime content) can be used to predict compressive strength (qu). The results show that a power function adapts better the relation qu versus η/Lv, in which Lv is adjusted by an exponent (in this case 0.11) for all coal fly ash—carbide lime mixtures studied. This correlation allowed the comparison of the unconfined compression strength between 1, 3, and 7 days in steam curing at 40 and 60°C with 7, 14, 28, 180, and 360 days at standard laboratory curing temperature (23°C) for different proportions of porosity and carbide lime content. The comparison of standard laboratory curing temperature and accelerated curing allowed generating equations which determines the time required for fast steam cure (40 and 60°C) to provide the same resistance for extended periods under standard laboratory curing temperature (23°C).