ShanDong Provincial Key Laboratory of Preparation and Measurement of Building Materials

Jinan, China

ShanDong Provincial Key Laboratory of Preparation and Measurement of Building Materials

Jinan, China
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Wang J.,University of Jinan | Wang H.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials | Yu J.,University of Jinan
Journal of Physics and Chemistry of Solids | Year: 2017

By modification of silane coupling agent, the TiO2 nanocrystal seeds layer was loaded on the surface of fly ash carriers. Based on that, the hydrothermal method was adopted to synthetize the one-dimensional (1-D) TiO2 which were loaded on the carriers densely under the condition of a low concentration TiO2 precursor. Because of the calcination residual of modifier, the transmission and diffusion of ions on the surface of TiO2 would be hindered, and the 1-D TiO2 with porous surface can be obtained. The specific surface area of porous TiO2/fly-ash composite particles reaches 174.8 m2/g. HRTEM and XRD results suggested that the TiO2 prepared was a single-crystalline structure featuring the (110) plane, but the plane had some structural defects for being bended and interrupted. Results of photocatalytic degradation of Rhodamine B showed that the catalytic activity of 1-D porous TiO2 was higher than that without a porous structure. © 2017 Elsevier Ltd


Hou P.,University of Jinan | Hou P.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials | Cheng X.,University of Jinan | Cheng X.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials | And 2 more authors.
Construction and Building Materials | Year: 2014

A dense surface structure of cement-based material is important for its resistance to the impacts of environment. Effectiveness and mechanisms of colloidal nanoSiO2 (CNS) and its precursor, tetraethoxysilane (TEOS), on surface-treatment of the one-month-old cement mortar by brushing technique were studied in this work. It revealed that CNS decreases the water absorption ratio of mortar when cured at 50 C and/or in sealed condition, but its effect is negligible when samples are cured at 20 C. A greater reduction of water absorption ratio is found in TEOS-treated mortar at 20 C or 50 C and under sealed or unsealed condition. Pozzolanic reaction between CNS/TEOS and Ca(OH)2 was observed by XRD, IR and EDS techniques. In addition, filler effects as revealed by SEM/EDS techniques were ascribed to for the densification of the exposed hardened mortar. Pore size distribution analysis conducted on mercury intrusion porosimeter showed that TEOS is more effective than CNS in filling pores finer than 50 nm, while CNS is found effective in filling capillary pores coarser than 50 nm. © 2013 Elsevier Ltd. All rights reserved.


Jiang F.,University of Jinan | Jiang F.,ShanDong Provincial Key Laboratory of Preparation and Measurement of Building Materials
Asian Journal of Chemistry | Year: 2013

In this study, Al2(SO4)3·18H 2O and ZrOCl2·8H2O were used as raw materials to synthesize Al2O3-ZrO2 nano-powder with an average diameter of 70 nm was prepared by co-precipitation method in the ultrasound field. The synthetic process and properties of nano-powder Al 2O3-ZrO2 were studied by X-ray diffraction, differential thermal analysis, scanning electron microscopy and laser particle size analyzer. The results show that because of the activation ultrasonic radiation can not only make the precursor smaller and reduce it agglomeration but also slow down the speed of change to gel. Ultrasonic radiation can refine Al2O3-ZrO2 nano-powder effectively. The product was sphere-shaped particle with good dispersity.


Jiang F.,University of Jinan | Jiang F.,ShanDong Provincial Key Laboratory of Preparation and Measurement of Building Materials
Asian Journal of Chemistry | Year: 2013

In this work, the surface modified ZnO nano-powder is prepared by the method of the combination of direct precipitation and in situ surface modification. The prepared samples are characterized by the means of laser particle size analysis, scanning electron microscopy, X-ray diffraction analysis and Fourier transform infrared spectroscopy. In the tribological test, by adding the surface modified ZnO nanopowder, the friction coefficient and the wear scar diameter of lubricants can be significantly reduced. The powder plays a role in antifriction.


Wang D.,University of Jinan | Yang P.,University of Jinan | Hou P.,University of Jinan | Zhang L.,University of Jinan | And 2 more authors.
Cement and Concrete Research | Year: 2016

SiO2 oligomers, a kind of intermedium between silane and SiO2 nanoparticles, reveal small size, hydrophilic property, and high affinity with cement paste. In cement-based materials, the SiO2 oligomers transform into SiO2 nanomaterials. This is first time to report SiO2 oligomers created by the hydrolysis and condensation reactions of tetraethyl orthosilicate in an acetic acid solution to reduce the water absorption rate and modify the surface microstructure of cement-based materials. Mild acetic acid makes the stable formation of SiO2 oligomers which promote the reaction with cement phases. Linear, branched and 3D-chain structures of SiO2 particles can be formed in sequence during the condensation of oligomers. The water absorption rate of cement mortars treated with SiO2 oligomers was reduced to 46.4%. The SiO2 oligomers were ideal candidate as a surface-treated agent which resulted in surface densification of cement-based materials. © 2015 Elsevier Ltd.


Hou P.,University of Jinan | Hou P.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials | Cheng X.,University of Jinan | Cheng X.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials | And 6 more authors.
Cement and Concrete Composites | Year: 2015

A reduced transport property of the superficial part of concrete structures is beneficial for enhancing their durability, due to the blocking of the migration of aggressive agents. In this study, influences of colloidal nano-SiO2 (CNS) with a mean particle size of 20 nm and its precursor, tetraethoxysilane (TEOS), on the transport properties of hardened cement pastes with water-to-cement ratios of 0.26, 0.38, 0.60 and 1.0 by mass were investigated by measuring the water absorption ratio and water vapor transmission coefficient, after the samples were first soaked in treatment agents for 1 h. Results showed that CNS and TEOS are capable of reducing the transport properties of hardened cement pastes by altering the pore structures. CNS reduces the threshold value and volume of the pores larger than about 0.1 μm, while TEOS reduces the threshold value and volume of the pores smaller than 0.1 μm, and TEOS also reduces the ratio of the 'ink-bottle' pore volume to the throat pore volume to a greater extent. A linear relationship between the volume of capillary pores smaller than 0.1/0.01 μm and the transport property was found, which can be ascribed to the reduction of transport properties of hardened cement pastes after surface-treatment with CNS or TEOS. © 2014 Elsevier Ltd. All rights reserved.


Hou P.,University of Jinan | Hou P.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials | Qian J.,Chongqing University | Cheng X.,University of Jinan | And 2 more authors.
Cement and Concrete Composites | Year: 2015

The aim of this work is to understand the characteristics of the pozzolanic reactivity of nanoSiO2 from studies of its pozzolanic reaction kinetics, morphology and structure of the hydrates and the influences of these features on the properties of cement-based materials, so as to explore a more targeted way of using nanoSiO2 in cement or concrete. It revealed that the pozzolanic reaction of nanoSiO2 is of the first-order and the apparent reaction rate constant of nanoSiO2-4 nm is about one order of magnitude bigger than that of silica fume, but the specific reaction rate constant is about one half to that of silica fume. A compacter gel structure and poorer crystallinity of the hydrates of nanoSiO2 to those of silica fume are found, as well. The rate of hydration of cement at very early ages is enhanced by nanoSiO2, but the rate slows down with aging due to the compact gel structure. To make the use of the high pozzolanic reactivity and ultrafine particle size of nanoSiO2, as well as its resulting compact gel structure, colloidal nanoSiO2 was applied onto the hardened cement mortar by brushing technique and a less permeable surface was resulted, which shows the potential of using nanoSiO2 as a surface treatment material for cement-based materials. © 2014 Elsevier Ltd. All rights reserved.


Liu M.,University of Jinan | Wang Z.,University of Jinan | Wu J.,University of Jinan | Li Q.,University of Jinan | Li Q.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials
Journal of Alloys and Compounds | Year: 2015

Abstract A range of Ti/Al2O3 composites with different Nd2O3 content (0-5 vol.%) were fabricated by vacuum hot pressing sintering at 1420 °C for 1.5 h under the pressure of 30 MPa. The sintered samples with Nd2O3 additives exhibited more superior performances than those without additives. When 3.0 vol.% Nd2O3 was added, Ti/Al2O3 composite showed optimal density (relative density of 98.79%), hardness (Vickers hardness of 15.87 GPa), strength (flexural strength of 412.45 MPa), toughness (fracture toughness of 8.77 MPa m1/2) and oxidation resistance (oxidation depth of ∼244 μm). However, excessive additive (>3.0 vol.%) would weaken these positive effects. SEM results revealed that the superior performances could be attributed to the grain refinement and microstructure densification. Moreover, plate-like grains were found at the interface and additional experiments demonstrated that their formation was caused by enrichment of Nd element, which is beneficial to the microstructure densification. © 2015 Elsevier B.V.


Cheng X.,University of Jinan | Cheng X.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials
Kuei Suan Jen Hsueh Pao/Journal of the Chinese Ceramic Society | Year: 2015

Barium (strontium) calcium sulphoaluminate is a novel and derivative mineral compound of calcium sulphoaluminate by the partial substitution of barium or strontium for calcium, possessing the distinct properties of low calcination temperature, fast setting, high early strength, slight expansion as well as good corrosion resistance. This paper was to represent these types of cement. The crystal features, calcinations process as well as hydration theory of barium (strontium) calcium sulphoaluminate were investigated. The performances like the mechanical properties, corrosion resistance as well as permeability were obtained for barium (strontium) calcium sulphoaluminate cement. Moreover, alite-barium (strontium) calcium sulphoaluminate cement and belite-barium (strontium) calcium sulphoaluminate cement were fabricated via mineral combination techniques as the developed cements with the superior performance. Moreover, the practical application of these cement in-site was described, indicating a great potential for use in harsh environments. © 2015, Chinese Ceramic Society. All right reserved.


Sun K.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials | Zhou X.,Brunel University | Gong C.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials | Ding Y.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials | Lu L.,Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials
Construction and Building Materials | Year: 2016

An improved method for the densified mixture design algorithm and Fuller curve were used to design high-density sulphoaluminate cement concrete (HDSC). The performance of HDSC is significantly influenced by the paste thickness on the coated aggregates. Sulphoaluminate cement concrete mixtures containing aggregates coated with 3 different paste thickness of t = 10 μm, 20 μm, and 30 μm and water-binder ratios of 0.25, 0.30 and 0.35 were prepared. The results of experiments show that paste thickness on the coated aggregates significantly influences the mechanical properties and durability of HDSC. With the increase of paste thickness, the compressive strength is increased, but the electrical resistivity is decreased, particularly at the early ages of 1 and 3 days. The sulfate corrosion resistance coefficients of HDSC are larger than 1.0, the total porosity can be less than 7%, and the micropore (i.e. with pore size less than 20 nm) can be larger than 70%. © 2016, Elsevier Ltd. All rights reserved.

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