Early Age Carbonation of Fiber-Cement Composites under Real Processing Conditions: A Parametric Investigation

Abstract

This paper presents the outcome of a comprehensive experimental program undertaken to study the performance of cellulose pulp and synthetic PVA (polyvinyl alcohol) based fiber-cement composite under both carbonated and non-carbonated curing conditions at early age. The composites were produced at different rolling pressures (2.5 to 9.0 bar) and subjected to various curing conditions in which the effects of CO 2 pressure (1 to 3 bar) and curing time (3 to 9 h) were studied. The mechanical properties (modulus of elasticity (MOE), modulus of rupture (MOR), and toughness), as well as the physical properties (porosity, bulk density, and water absorption), were measured for all samples. Scanning electron microscopy (SEM) was used to investigate the effect of carbonation on porosity change and adhesion of fiber-matrix. A parametric investigation of the effects of the carbonation curing period, CO 2 pressure, and rolling pressure on the improvement of the physical and mechanical properties during carbonation curing was performed. Results showed that fiber-cement composites cured with an elevated CO 2 pressure of 3 bar, rolling pressure of 3 bar, and 5 h of curing time provided optimal curing conditions resulting in the most desirable mechanical and physical properties. However, toughness was greatly reduced with the increase of the CO 2 pressure, curing time, and rolling pressure. Additionally, the carbonation curing improved the bonding between the fiber and the cement matrix because of the precipitation of calcite particularly in the pores of the interfacial transition zone (ITZ) between the cement matrix and the fibers.

Conservation Environments’ Effect on the Compressive Strength Behaviour of Wood–Concrete Composites

“…In general, vegetated concrete has a high porosity. Indeed, the SEM pictures of a significant variety of fibre cements in the literature exhibit several fields when compared to regular concrete [ 82 , 83 , 84 , 85 , 86 ]. As a result, the addition of wood fibres to concrete enhances its density.…”

Morphological characteristics of calcium carbonate crystallization in CO2 pre-cured aerated concrete

“…27 Kottititum et al found that when the curing pressure was increased from 1 to 3 bar (0.1-0.3 MPa), the modulus of rupture of ber-cement composites increased by 16%, the modulus of elasticity increased by 23%, and the toughness decreased by 51%. 28 Tu et al observed that CO 2 pressure (0.01 and 0.4 MPa) impacted the crystalline of CaCO 3 for cement specimens mixed with limestone powder. 29 Extensive reports have supported the multiple benets of carbonation to CBMs at early ages in terms of CO 2 sinking and engineering performance improvement.…”

The influence of water-cement ratios and alumino-silicate based accelerator on the properties of fiber-reinforced cement composites

“…The ASC process usually takes about 24 h (1 day) by using the curing temperature between 160℃ to 180°C and pressure between 8 bar to 12 bar. [2][3][4][5][6][7][8].…”