Behavior of Polymer Grouted Sand and Polymer Modified Smart Cement with Verification of New Failure Model for Concrete
In this study acrylamide polymer was added to the smart cement and the rheological, mechanical and corrosion resistance properties of the resultant composites were studied. Also, the effect of acrylamide polymer modified grouts to further enhance the physical, mechanical and sensing properties from the time of mixing through pumping and final setting. Wet and dry cycle of acrylamide polymer grouted sand modified with algae was studied and the electrical sensing ability of composition was verified using the weight measurements. Splitting tensile strength of grouted sand prepared without and with algae increased by 118% and 130% to 180% respectively after one wet and dry cycle. The test results showed the moisture loss and chemical shrinkage of the smart cement was reduced with addition of 2.5% concentrated acrylamide polymer from 1.2% to 0.1% and from 4.6% to 0.4% respectively. Identified that the flowability of smart cement was reduced after high concentrated acrylamide polymer modification. Rheological properties of acrylamide polymer, smart cement and acrylamide polymer modified smart cement were modelled using Modified Bingham model, Herschel Bulkley model and Vipulanandan rheological model. Based on the coefficient of determination and root mean square error, Vipulanandan model predicted the test results well. Also, the investigation of rheology of polymer modified cement with UH biosurfactant showed that it improved the workability of acrylamide polymer modified cement and showed 16% increase in the maximum shear stress (τmax). API (30 minutes) fluid loss was 131.4 mL for smart cement with addition acrylamide polymer, the fluid loss was reduced to 77.3mL - 83.8 mL. Splitting tensile strength of smart cement was increased by 22% with the addition of 2% acrylamide polymer and the piezoresistivity at peak stress was 35% which reduced to 18% with the addition of 1.5% polymer. Based on over 300 uniaxial, biaxial and triaxial test data on plain concrete with uniaxial compressive strength in the range of 22 MPa to 70 MPa were used to verify the Vipulanandan generalized concrete failure model.