Ecological risk assessment of soil and water loss by thermal enhanced methane recovery: Numerical study using two-phase flow simulation

Magnesium phosphate cement (MPC) paste is hardened by the acid–base reaction between magnesium oxide and phosphate. This work collects and evaluates the thermodynamic data at 25 ℃ and a pressure of 0.1 MPa and establishes the hydration reaction model of MPC pastes. The influence of the magnesium–phosphorus molar (M/P) ratio and water-to-binder (W/B) ratio on the hydration product is explored by the thermodynamic simulation. Following this, the initial and ultimate states of the hydration state of MPC pastes are visualized, and the porosity of different pastes as well as fractal analysis are presented. The result shows that a small M/P ratio is beneficial for the formation of main hydration products. The boric acid acts as a retarder, has a significant effect on lowering the pH of the paste, and slows down the formation of hydration products. After the porosity comparison, it can be concluded that the decreasing of M/P and W/B ratios helps reduce porosity. In addition, the fractal dimension Df of MPC pastes is positively proportional to the porosity, and small M/P ratios as well as small W/B ratios are beneficial for reducing the Df of MKPC pastes.

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Fractal Analysis on Pore Structure and Modeling of Hydration of Magnesium Phosphate Cement Paste

Embedded smart PZT-based sensor for internal damage detection in concrete under applied compression

Meso-damage evolution analysis of magnesium oxychloride cement concrete based on X-CT and grey-level co-occurrence matrix

Glass fiber reinforced gypsum composites with microencapsulated PCM as novel building thermal energy storage material

Analysis of micro-structural damage evolution of concrete through coupled X-ray computed tomography and gray-level co-occurrence matrices method

Quantitative study of meso-damage process on concrete by CT technology and improved differential box counting method

In this study, a multivariate analysis of light-weight aggregate concrete embedded by microencapsulated phase change material (MPCM-LWAC) was performed by assessing the effect of water-cement ratio (0.5,0.55, and 0.6), MPCM content (0%, 2.5%, 5.0%, 7.5%, and 10%), curing time (3 d, 7 d, 14 d, and 28 d), as well as MPCM state (liquid and solid state) on the compressive strength , splitting tensile strength , and elasticity modulus. In order to understand the mechanism of the strength change, porosity, SEM images and adiabatic temperature rise of MPCM-LWAC were measured. Results shown that porosity of MPCM-LWAC is linearly proportional to the water-cement ratio, while with the increase of MPCM content, the growth rate of porosity of MPCM-LWAC with the larger water-cement ratio grow more slowly than that of MPCM-LWAC with the lower water-cement ratio, which is contrary to the changes of compressive and splitting tensile strength of MPCM-LWAC. The growth rate of compressive and splitting tensile strength at each age reduces with increasing amount of MPCM, which attributes to the delay in the hardening time of the cement. When MPCM-LWAC samples are subjected to temperature greater than the melting temperature of MPCM, the mechanical behaviors of MPCM-LWAC slightly reduced. The addition of MPCM to LWAC resulted in a linear reduction in elastic modulus . In addition, SEM images showed that no phase change material leakage was found in the damaged specimens.

Multivariate analysis of effects of microencapsulated phase change materials on mechanical behaviors in light-weight aggregate concrete

Experimental investigation of the thermal and mechanical properties of lightweight aggregate concrete mixed with microencapsulated phase change materials

Comparative study on the meso-scale damage evolution of concrete under static and dynamic tensile loading using X-ray computed tomography and digital image analysis

Weihua Ding

Papers

Analysis of micro-structural damage evolution of concrete through coupled X-ray computed tomography and gray-level co-occurrence matrices method

Quantitative study of meso-damage process on concrete by CT technology and improved differential box counting method

Multivariate analysis of effects of microencapsulated phase change materials on mechanical behaviors in light-weight aggregate concrete

Experimental investigation of the thermal and mechanical properties of lightweight aggregate concrete mixed with microencapsulated phase change materials

Comparative study on the meso-scale damage evolution of concrete under static and dynamic tensile loading using X-ray computed tomography and digital image analysis