Regression Analysis for the Axial Strengths of Muti-Blended Steel Fiber Self Compacting Concrete from the Experimentation.

The present paper deals with triple blended Self-Compacting Concrete (SCC) where 53 grade of cement is blended with flyash and Condensed Silica Fume (CSF) at different percentages as replacements to the cement. The steel fiber of diameter 1mm; with an aspect ratios varying from 20,30 and 40 were mixed to get the higher mechanical properties such as compressive and tensile strengths at four different percentages. The required number of cube and the cylindrical specimens of triple blended steel fibrous SCC were prepared and evaluated for compressive and the tensile strengths. The magnitude of the test results have indicated that there is enhancement in the axial strength properties of this type of the concrete as the percentage of steel increases up to certain value to fulfil the needs of the SCC as per the America Concrete Institute (ACI) norm. The regression equation is derived for the experimental values for the compressive and the spilt tensile strength of steel fibere self-compacting concrete (SFSCC) and verified acceptance the equation. The results of present investigation would help in the preparation of optimum tri- blended steel fibrous SCC ,which are suitable for practical usages like floor slabs bridge decks, important highways, airport runways and thin shaped concrete structural elements.

Special Binding for Refractory Concretes

The paper shows data related to coexistence of various binding systems, which could be present during the hardening of special concretes. It is taken into account the Ultra Low Aluminous Cement Concretes additivated with different materials (phosphates and mineral ultra dispersed powders - Condensed Silica Fume, Hydrated Alumina etc). In correlation to the pH-value, these substances can favour the forming of new binding systems besides the hydraulic binder (which is not important in this case). The new system is the coagulation binding form. The coagulation binding system has a very important role in the advanced compactness and in the increasing mechanical strengths of concrete structures.