The influence of ground blast furnace slag and plasticizing additive on the strength properties of road concrete

Abstract

The article presents results of the latest generation of different dosages of polyacrylate superplasticizer Dynamon SP 1 in a wide concentration range influences the strength properties of road concrete based on Portland cement with partial replacement with ground blast furnace slag.  To compare the strength properties, concrete based on Portland cement without replacement with ground blast furnace slag and with the addition of polyacrylate superplasticizer Dynamon SP 1 in the same range was also studied. Experimental studies of the change in compressive and flexural tensile strengths of a Portland cement-based mortar with its partial replacement with ground blast furnace slag in the range from 0% to 20% were conducted. It was concluded that the Portland cement replacement in an amount of 10-14 % with ground blast furnace slag is quite acceptable, which is due to a moderate decrease in strength indicators. The concentration of the acrylic superplasticizer Dynamon SP 1 was determined, which corresponds to the maximum compressive and flexural tensile strengths of сementconcrete based on Portland cement without partial replacement with ground blast furnace slag. This concentration is 1 % for compressive strength and 1,25 %  for flexural tensile strengths. The concentrations of the superplasticizer Dynamon SP 1 were also determined, which provide the maximum compressive and flexural tensile strengths of concrete based on Portland cement with partial replacement with ground blast furnace slag. It turned out that the maximum value itself with the use of Portland cement with partial replacement with ground blast furnace slag is somewhat smaller, compared to the maximums when using Portland cement without partial replacement with ground blast furnace slag: for compressive strength by 3-10% and flexural tensile strengths by 6-9%, depending on the amount of binder. It was also found that the superplasticizer concentration corresponding to the maximum flexural tensile strength of concrete based on Portland cement with partial replacement, compared to concrete based on Portland cement without partial replacement, is somewhat different. The value of this concentration is 1,1 %