Compressive behaviors of ultra-low-weight foamed cement-based composite reinforced by polypropylene short fibers

Abstract

With advantages in sustainability, low thermal conductivity, and self-weight, the foamed cement-based composites have captured tremendous attention in various low strength structural and nonstructural applications. This paper aimed to investigate the effects of the short polypropylene fibers on the quasi-static compression performance of the ultra-low-weight foamed cement-based composites. The results show that the elasticity modulus, peak strength, and ultimate linear strength of the fiber-reinforced composites are increased by 208%, 42%, and 71%, respectively. The plateau stress and the densification strain energy of fiber-reinforced composites are improved by up to 49% and 47%. Simultaneously, the failure mode of the fibrous sample is altered from a brittle behavior to plastic behavior. The significance of this work shows that short synthetic fibers can improve the compressive capacity considerably, turning out to be an effective strategy for obtaining higher mechanical strengths associated with ultra-low-weight typical cement-based elements. According to the experiment results, a constructive damage model is carried out to describe the compressive properties of short PP fiber-reinforced composites. Thus, such theoretical curves can describe the compression behavior successfully and can be potentially applied in practical project and numerical simulation. This work can also be useful toward the foundation of optimal design for toughening behavior in fiber-reinforced lightweight cement elements.

Effects of high temperature on the mechanical behavior of calcium silicate hydrate under uniaxial tension and compression

“…The molecular simulation obtained in our study illustrates that the residual strength of CÀSÀH grains under tension and compression is between 2 GPa and 10.0 GPa, which are much larger than that of cement paste (2 MPa for the tensile strength and 20 MPa for the compressive strength (Liu et al, 2020;Moradi et al, 2020;Shahrin and Bobko, 2017;Yan et al, 2019;Yang et al, 2020;Zhang et al, 2019;Zhang et al, 2020c). Intriguingly, the residual tensile strength can to some extent grows with temperature and the compressive strength undergoes a slight evolution with temperature except that a decrease for C/S ¼ 1.10 or C/S ¼ 1.33 in the x and y directions but a clear increasing trend for C/S ¼ 1.10, which suggests the failure mechanism of CÀSÀH grains is different from that of cement paste.…”

Engineering Properties and Applications of Air-Foamed Lightweight Soil

“…e addition of 0.15% sisal fiber can increase the flexural strength of air-foamed lightweight soil by 29% [107] because the crack localization is limited and ductility is improved after the addition of fiber-reinforced materials [50]. In terms of fibers used, polypropylene fiber has been applied more extensively [108][109][110]. Polypropylene fiber has a better improvement effect than other fibers under the same conditions, and its price is very low [46,111].…”

A micromechanical crack bridging model considering the slip-softening interface with the residual shear stress for SFRCC

“…The stress transfer from the matrix to the fibers is achieved through the shear stress (or rather, the bond) at the fiber/matrix interface. The role of fibers in the composite is to delay the occurrence of cracks and restrain their propagation through fiber bonding, debonding and pullout processes, thus greatly improving the mechanical properties such as the bearing capacity, energy dissipation capacity (or rather, ductility), toughness and impact resistance (Aslani and Nejadi, 2012;Cunha et al, 2010;Lee et al, 2010;Moradi et al, 2020;Xu et al, 2011Xu et al, , 2012Yang et al, 2020;Zacharda et al, 2017;Zhang et al 2013). This is the so-called crack bridging effect, the main mechanism of fiber reinforcement.…”