Changing the method of compaction of autoclaved building materials modified by diabase and barite aggregate.

Abstract

The traditional way of producing sand-lime products is connected with the use of three basic raw materials i.e. quartz sand of natural origin, water and quicklime ground lime. During hydrothermal treatment in an autoclave, chemical reactions take place between the calcium and silicon ions. As a result of these reactions, the products are created that provide advantageous appropriable traits. In order to improve the durability attributes of the discussed products, diabase and barite aggregate was introduced into the raw material mass. In addition, the change in the densification method of the silicate mixture was applied. Layering was replaced instead of traditional pressing. The article describes sand-lime products modified with diabase and barite aggregate in an amount up to 15% by weight. Two methods of thickening the sand-lime mixture were used: pressing and layering. The change of the applied technology significantly influences, among others for water absorption. The best result was obtained using 5% and 10% modifiers. Modification with 5% content of diabase aggregate and 5% content of barite aggregate increases the strength by over 60% in relation to the reference sample. The obtained properties are reflected in the image of the microstructure examined by means of the scanning electron microscope. In the sand- lime products, both traditional and modified with diabase and barite aggregates, the C-S-H phase and tobermorite is present. These phases are characteristic for autoclaved products, although depending on the method of thickening occur in varying degrees and intensities.