Abstract:Ti-bearing blast furnace slag pastes were modified with PS (polystyrene), PVAC (polyvinyl acetate) and SAE (styrene-acrylate emulsion) respectively, to prepare the non-autoclaved and unburnt bricks. The major factors influencing the properties of the products and the modification mechanism were investigated. The samples modified with SAE and PVAC show better properties than those with PS. Being the best modifying agent of the three, SAE addition results in the samples with a compressive strength 37.7 MPa and flexural strength 13.9 MPa, when the samples have a composition of slag 72%, SAE 10% and additive 18%, is cast at pressure 30 MPa and cured for 7 d. The study reveals that the acid radicals in SAE react with the metal ions in the slag to form complex compounds.