Mechanical properties and microscopic characterization of waste perlite powder as supplementary cementitious material.

In this study, we conducted a comprehensive investigation on the influence of waste perlite powder (WPP) on the various properties of mortar and paste, including slurry performance, mechanical strength, hydration products, and microstructure. Additionally, we also aimed to uncover the underlying mechanism behind these effects. It was found that WPP reduced the workability and facilitated the setting process of cement-WPP pastes.

Assembling phenyl-modified colloidal silica on graphene oxide towards ethanol redispersible graphene oxide powder.

Recently, ethanol has shown promising potential in the large-scale reduction of graphene oxide (GO) into graphene. However, dispersion of GO powder in ethanol is a challenge due to its poor affinity, which hinders permeation and intercalation of ethanol between GO molecule layers. In this paper, phenyl-modified colloidal silica nanospheres (PSNS) were synthesized by phenyl-tri-ethoxy-silane (PTES) and tetra-ethyl -silicate (TEOS) using a sol-gel method.

Cement-Based Materials Modified by Colloidal Nano-Silica: Impermeability Characteristic and Microstructure.

Colloidal nano-silica (CNS) was used to improve the mechanical and impermeability characteristics of mortar in this study. The samples were prepared with 0%, 1%, 2% and 3% (solid content) CNS addition. The mechanical strength and permeability of each mixture was studied, and the mechanism behind was revealed by hydration heat evolution, XRD, DSC-DTG, Si MAS-NMR and SEM-EDS analysis.

The CO fertilization effect on leaf photosynthesis of maize ( L.) depends on growth temperatures with changes in leaf anatomy and soluble sugars.

Understanding the potential mechanisms and processes of leaf photosynthesis in response to elevated CO concentration ([CO]) and temperature is critical for estimating the impacts of climatic change on the growth and yield in crops such as maize ( L.), which is a widely cultivated C crop all over the world. We examined the combined effect of elevated [CO] and temperature on plant growth, leaf photosynthesis, stomatal traits, and biochemical compositions of maize with six environmental growth chambers controlling two CO levels (400 and 800 μmol mol) and three temperature regimes (25/19°C, 31/25°C, and 37/31°C).

Effect of TIPA on mechanical properties and hydration properties of cement-lithium slag system.

Effect of triisopropanolamine (TIPA) on compressive strength and hydration properties of cement-lithium slag (LS, 30%) paste was studied. The results demonstrated that the addition of TIPA is advantageous for compressive strength at 7 d, 28 d and 60 d. The reason was related to the pore complexity and hydration process of cement and LS.

Preparation of ultrafine fly ash by wet grinding and its utilization for immobilizing chloride ions in cement paste.

In this study, to promote the chloride binding capacity of coal fired fly ash (RFA) in cementitious materials, wet grinding was employed and ultrafine fly ash (UFA) with D50 = 2.1 μm was prepared; SEM, XRD, TG, FTIR, and XPS were used to evaluate the chemical and physical change in the process of wet grinding. Then, two kinds of binders composed of cement and FA were designed, and the chloride immobilization was comparatively studied in terms of chemical binding, physical binding, and migration resistance.

Effect of sodium gluconate on molecular conformation of polycarboxylate superplasticizer studied by the molecular dynamics simulation.

Sodium gluconate (SG) has been accepted as one of the main additional components in polycarboxylate superplasticizer (PCE) system, due to its excellent retarding effect. While the negative effect on dispersion of PCE was reported in the literature, the reason was not completely revealed. In this study, molecular dynamics simulation was used to investigate the mutual influence between SG and PCE in calcium hydroxide (CH) solution.

Effect of Polyacrylic Acid on Rheology of Cement Paste Plasticized by Polycarboxylate Superplasticizer.

Viscosity-enhancing agents (VEA) have been widely employed in high flowability cement-based materials, so as to ensure that no bleeding and segregation would occur. However, in most cases, interaction between VEA and superplasticizer would be unavoidable. In this study, the effect of polyacrylic acid (PAA), known as one of the most commonly used VEAs, on rheology performance of cement paste containing polycarboxylate superplasticizer (PCE), was studied.

Preparation and thermal insulation performance of cast-in-situ phosphogypsum wall.

Introduction: The mass accumulation of phosphogypsum has caused serious environmental pollution, which has become a worldwide problem. Gypsum is a kind of green building material, which is lighter, has better heat and sound insulation performance, and is easier to recycle compared to cement. The application of cast-in-situ phosphogypsum wall could consume a large amount of pollutant, and improve the efficiency of building construction.

Stabilization/solidification on chromium (III) wastes by C(3)A and C(3)A hydrated matrix.

Hazardous wastes are usually used in the Portland cement production in order to save energy, costs and/or stabilize toxic substances and heavy metals inside the clinker. This work focus on the stabilization/solidification on chromium (III) wastes by C(3)A and C(3)A hydrated matrix. The immobilization rate of chromium in C(3)A and the leaching characteristics of the C(3)A hydrated matrixes containing chromium were investigated by ICP-AES.

[Environment load from China's cement production].

Based on the life-cycle theory, a quantitative evaluation of the environment load caused by cement manufacturing in China was carried out with the application of the CML. environmental impact assessment method. The results show that global warming potential, energy depletion potential and abiotic depletion potential make the main contribution to the environment impact, their environmental loads corresponding to identical environmental impact sorts being 2.