Response of Self Compacting Cementious Systems (SCCS) Using Lime Stone Powder (LSP) and Marble Powder (MP)

Abstract

Self-Compacting Cementitious Systems (SCCS) have emerged as modern technology in the field of advanced concrete materials which are being used extensively throughout the world after carrying out successful research work on use of secondary raw materials in self-compacting cementitious systems (SCCS). This research study was made to evaluate the suitability of locally available Lime stone powder (LSP) and Marble Powder (MP) as a partial replacement of cement in self-compacting cementious systems with ultimate goal to locally produce self-compacting concrete (SCC) with desired environmental friendly properties. Based on the results it was concluded that the secondary raw materials used in this research enhance the properties of SCCS in both fresh and hardened states. The particle morphology of secondary raw materials along with their physical and chemical properties all effect the water demand, super plasticizer demand and flow behaviour of SCCS. Lime stone powder was prepared by grinding Margallah crush in a local flour mill by providing them with special sieves and marble powder was collected in slurry form from a marble factory near Islamabad which was dried afterwards. At higher replacement levels more than 10%, SCP systems based on lime stone powder (LSP) has higher water demand as compared to marble powder (MP) and also higher superplasticizer demand for the target flow.MP acts as a better accelerator for self-compacting cement formulation as it enhances the early hydrations kinetics revealed in calorimetry leading to a higher early age strength up to 7 days as compared to lime stone powder (LSP). In self-compacting formulations, 10% replacement of cement by LSP, MP or their blend gave the optimum results both in terms of flowability and strength in all self-compacting cementious systems. LSP based formulations gave better strengths as compared to MP or blended formulation of both SRMs (LSP and MP, 50:50 by mass) mixed at the same replacement level in all three SCCS systems. It has been established that T25 cm time and T30 cm time have a linear relation both in case of SCPs and SCMs and this relation is similar to T50 cm time and T70 cm time for SCC system. Similarly T25 cm time and V-funnel times for SCMs have a linear relation and both indicated the viscosity of system as suggested by Rizwan (2006). Self-compacting concrete samples were casted and tested as per EN 196 (4x4x16 cm3 prisms) and BS EN 12390-1 (4”x4”x4” cubes). It has been established that both standards gave reasonable matching results with EN 196 being preferred over BS EN 12390-1 for the reasons of economy and for giving both flexural and compression strengths. After the detailed analysis of all the results, it can also be stated that both secondary raw materials investigated, can be successfully used in making self-compacting concrete systems in Pakistan.