Experimental Study on CaCO₃ Whisker-Reinforced Fiber Cement Mortar

Abstract

As a kind of monocrystal reinforcing material, CaCO3 whisker has good characteristics of high strength, high module and high thermal stability. This research aims to optimize the microscopic structure of fiber cement mortar by adding CaCO3 whiskers and improve the macroscopic mechanical properties. The results showed that CaCO3 whiskers increased the flexural and compressive strength of cement mortar at 3d age by 29.5% and 19.8% at maximum respectively, which fell to 7.2% and 13.0% at 28d age; when CaCO3 whiskers content was 10% and polypropylene fibers content was 0.05%, compared with the pure cement mortar, the flexural and compressive strength were increased by 32.4% and 29.4% at 3d age and 7.6% and 4.6% at 28d age respectively; when the fiber length was 9mm, the composite effect of whiskers and fibers was more ideal; through the SEM analysis, the reinforcing mechanisms of CaCO3 whiskers and polypropylene fibers in cement mortar were discussed.

Experimental Study on Impact Resistance of CaCO₃ Whisker-Reinforced Cement Mortar

“…In this research, CaCO 3 whiskers were added into cement mortar to reinforce the impact resistance. Through the previous research, it was indicated that CaCO 3 whiskers could improve the flexural and compressive strength of mortar significantly [4]. Therefore, this study expected that the impact resistance of cement mortar could be improved with the incorporation of CaCO 3 whiskers of good physical and mechanical properties.…”

Mechanical Attributes of Uniaxial Compression for Calcium Carbonate Whisker Reinforced Oil Well Cement Pastes

“…In Figure 20(c), caused by the rising stress, the collapsing strength of CaCO 3 whiskers far exceeded the cement paste cohesion strength; the crack could not break down the CaCO 3 whiskers; instead the CaCO 3 whiskers could be pulled out to consume the energy for rubbing action and stripping effect [15,16]. Also the crack would be impeded by CaCO 3 whiskers [3,[17][18][19][20] as in Figure 20(d). This was marked by the red circle in Figure 20(e); over the ultimate high dosage, the CaCO 3 whiskers could be scattered unevenly; in reverse the whisker would ease the mechanical property of cement paste, whereby the strengthening effort of the CaCO 3 whiskers would be summed up as the destroying energy conservation and microcrack inhibiting and a physical model was stated in Figure 20.…”

“…Cao et al [1,2] have firstly explored the calcium carbonate whiskers in the cement based composite as reinforcing material, and the result of the study shows that the compressive strength, flexible strength, and tensile strength of the cement pastes with calcium carbonate whisker are increased. Cao et al [3] have researched the cement pastes with hybrid fibers of calcium carbonate whisker and basalt fiber which displays that the hybrid effect with different kinds of fibers could arise in the cement pastes and the mechanical property of the cement pastes would be improved further than with just single fiber. Simultaneously, with the perfect performance of high strength, high elasticity modulus, excellent heat-resisting, and heat insulation, the calcium carbonate whisker as a kind of desired filling material could fit the requests of the cementing and geological engineering in petroleum industry well [1,4].…”