Effect of ionic stabilizer on the durability performance of cement stabilized gangue bonding material

Cement-stabilized gangue bonding material for road projects in cold areas is very susceptible to frost damage. The appropriate amount of added stabilizer is an important way to enhance its road durability performance.The effects of ionic gangue stabilization( ICG) admixture(0,0.005%,0.010%,0.015%,0.020%) on the strength and durability of cement-stabilized gangue bonding material(CS) were studied through 7 d unconfined compressive strength test,temperature shrinkage test,water penetration test,scouring test and freeze-thaw test,respectively. Using mercury-pressure test(MIP),X-ray diffraction(XRD),Fourier infrared spectroscopy(FTIR) and combined thermogravimetric-micro-commercial thermogravimetric method(TG-DTG),the effect of ICG on the pore structure and hydration products of CS,and their action mechanism were analyzed. In addition,the fractal characteristics of the pore structure of ICG-stabilized CS were investigated based on the data of the mercury-pressure test, and the link between the fractal dimension D_s and the durability of CS was constructed. The results showed that after CS was mixed with ICG,the weakly bound water was transformed into free water,while the Ca²⁺ concentration in the aqueous solution increased,which promoted the generation of hydration products,and pore structure complexity. Also,it made the value of D_s increase, the pore volume decrease, the porosity decrease, and the CS pore structure confinement increase.In turn,it improved the compressive strength,temperature shrinkage resistance,seepage resistance,scour resistance,and frost resistance of CS,thus,improving the CS durability performance. The stabilization effect of ICG was most significant when the ICG doping amount was 0.010%. In addition,there was a linear relationship between the fractal dimensionDsand the durability parameters of CS,so D_s could be used as a new parameter to evaluate the durability of cement-stabilized gangue binders. The research results can provide some references for the application of ionic stabilizers in cement-stabilized gangue binding materials.