Advanced Materials Research Vols. 557-559

Abstract: Sulfur Extended Asphalt Modified (SEAM) is a newly developed asphalt modifier. The principal purpose of this paper is to study the performance of SEAM modified asphalt under the low temperature. Through the Low-temperature splitting test and the Low-temperature bending test .It indicated that the SEAM enhances the performance of asphalt under the low temperature.

Abstract: This paper describes a pilot process for the comprehensive utilization of coal refuse. During the process, alumina was first extracted from coal refuse, the residue was then used to calcine cement clinker, and all of the waste gases and water were recovered and re-used in the process of alumina extraction. During the first process, the appropriate temperature regimen and temperature distribution were determined based on laboratory results in a tunnel kiln, and were optimized during the pilot process. The most important step of the temperature regimen is the increasing rate within the temperature range of 500–600°C. And the last determined temperature regimen is suitable to be used in the other industrial kiln when the other processes are applied for the extraction of alumina from coal refuse. The extraction rate for alumina has also been investigated in the pilot tests, and it is a bit lower than those obtained in the laboratory tests. Two methods were used for the calcination of cement clinker. The clinker calcined directly from the adjusted residue could be used for applications with low strength demands, whereas the clinker calcined from the residue and the raw materials of the Portland cement clinker could be used normally.

Abstract: The compressive strength and the flexural strength of CA mortar at different temperature conditions were all tested. We have found that temperature has great influence on the mechanical properties of CA mortar. As the temperature increase from -40°C to 60°C, its compressive strength decrease from 31.7MPa to 1.5MPa for CRTS I type CA mortar, while the same rule can be found to the flexural strength. Results also showed that as the content of asphalt in mortar increases, the temperature sensitivity of mechanical properties increases.

Abstract: Class F fly ash-based geopolymers formed by pressure were prepared, and the preparation factors effecting on properties especially mechanical strength were discussed and optimized. The geopolymer specimens show excellent integrated properties such as mechanical strength, acid-resistance and water absorption and can be potentially applied to acid-resisting bricks except for acid-resistance left to be improved. The elevated curing temperature and the prolonged curing time are both beneficial to develop the mechanical strength as well as the moderately increased forming pressure and quartz sand/fly ash ratio. Being pretreated at elevated temperature for proper time before press forming improves the mechanical strength and reduces the water absorption greatly.

Abstract: Naphthalene sulfonate formaldehyde condensate (FDN) is a kind of anionic surfactant which is consists of the hydrophobic naphthalene groups and hydrophilic sulfonate groups. Four FDN fractions with different molecular weights were prepared by using ultrafiltration and were determined by Electro Spray Ionization-Mass Spectroscopy (ESI-MS).The adsorption behavior of different fractions was investigated by means of ultraviolet spectrophotometer (UV spectroscopy), ZetaPlus and X-ray photoelectron spectroscopy (XPS). The results show that the adsorption of FDN with high molecular weight follows Langmuir model and belongs to monolayer adsorption on cement surface. However, the adsorption characteristic for FDN without ultrafiltration displays the multilayer adsorption. The greater adsorption amount and the adsorption layer thickness of FDN with higher molecular weight can provide sufficient steric hindrances between the particles. The electrostatic repulsion of particle surface has been found to increase with increase in the molecular weight of FDN.

Abstract: Calcium lignosulfonate (CL) was separated into three fractions with different molecular weight by using ultrafiltration membranes, and the effect of the composition of commercial CL on the setting time of Portland cement with anhydrite was studied in this paper. Results show that the CL fraction with the cut-off molecular weight of less than 150 (CL-A) shortens setting time most. Further analysis indicates that the content of reducing sugar in CL-A reaches to 15.3%, including mannose, glucose, galactose, xylose and arabinose, and these five kinds of monosaccharides are found to be the main components of inducing quick set of cement. Ultrafiltration is an effective method to remove most of the reducing sugar in CL and weaken the quick set of Portland cement with anhydrite.

Abstract: A kind of novel ash-calcium-powder internal wall coating was successfully prepared. The stability problem was resolved by adding the stabilizer synthesized in our own laboratory. The effect of vinyl acetate ester-ethylene (VAE) emulsion contents on the property of scrub resistance was studied. And the effect of ash-calcium-powder contents on the property of scrub resistance and contrast ratio were discussed. The results indicate that the scrub resistance increase with increasing the content of ash-calcium-powder or VAE emulsion. Also the scrub resistance is effected by the filming time. And it is shown that the longer, the better the scrub resistance.

Abstract: The adsorption of two superplasticizers, SNF and CE, on the cement particles were investigated. The results shown that, the adsorption of the superplasticizers could be described with Langmuir isothermal adsorption equation. The saturated adsorptive capacity of SNF and CE was 11.35 and 5.24 mg/g at 20°C, respectively. The adsorption of SNF was faster than that of CE. When the concentration of superplasticizer was 1.0 g/L, the ζ potential of the cement surface with SNF was -28.8 mV, while that with CE was -20.6 mV, indicating that the electrostatic repulsive force of SNF was stronger than that of CE. XPS spectrum disclosed the thickness of adsorption layer of CE and SNF on the cement surface was 9.8 and 1.5 nm, thus the steric repulsive force of CE was stronger. The dispersion experiment displayed that, the dispersion capacity of CE on the cement paste was much better than that of SNF.

Abstract: To the old cement concrete pavement which lost the overall loading capacity and large areas are damaged, by using rubblization technology to shocks, crushing and compaction it, pouring the warm-mix asphalt sealing, formed less than 60mm size of flexible base of gravel and paved with warm-mix asphalt pavement on this base. This article is about analysis of interlinear stresses of pavement structure and production cost analysis of mixture on this combination structure. Proved that the structure could in-place recycling, solving the environmental issues of dropped cement pieces garbage. Mix in mixture, spreading process of reducing harmful gas emissions, can save more than 30% of construction costs.

Abstract: Polymer modified straw fiber-reinforced cementitious composition（PSFC） prepared by polyacrylamide, straw fiber, industrial solid waste and cement, was a new type of and soil consolidation material. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) were used to identify major chemical composition and structure of the matrix-fiber interface. The results show that the polyacrylamide can efficiently improve the structure of matrix-fiber transition zone, and water-soluble polymer mixing amount acts significantly on its existing morphology.