Article ID Journal Published Year Pages File Type
258104 Construction and Building Materials 2013 8 Pages PDF
Abstract

•Mortars of high aggregate:binder ratios with alkali activated blast furnace slag were investigated.•Previous reports on similar mortar composition were not found.•Conditions included low alkali concentration to reduce cost and problems associated to alkalis.•Low water/binder ratios were used in mortars of semi-dry consistency for precast products.•The implications of the above are related to strength development and reactivity of the slag.

Mortars with high aggregate:binder ratios of 10:1 and 8:1 were investigated with binders of blast furnace slag activated with 2.5%, 3.4%, 4.5%, and 6.5% Na2O relative to the mass of slag and using sodium silicate solutions with moduli SiO2/Na2O of 1.3, 1.5, 1.7, 2.0 and 2.2. The mortars were formulated at low water/binder ratio in semi-dry mixes to produce bricks. The modulus of 1.7 was chosen as most adequate and the effects of the % Na2O and temperature, on strength development, were then investigated. Various formulations showed compressive strength useful for construction, where mortars with aggregate:binder of 8:1, activated with 3.5% Na2O and cured at 60 °C registered 20 MPa at 28 days, while mortars with 8:1 and 10:1 with 6% Na2O cured at 20 °C reached 20 and 13.3 MPa, respectively.

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Physical Sciences and Engineering Engineering Civil and Structural Engineering
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