Mechanical Property of Phosphoaluminate Cement

2010 ◽  
Vol 150-151 ◽  
pp. 1754-1757 ◽  
Author(s):  
Peng Liu ◽  
Zhi Wu Yu ◽  
Ling Kun Chen ◽  
Zhu Ding
Keyword(s):  
Mechanical Property ◽  
Compressive Strength ◽  
Phase Composition ◽  
Electrical Properties ◽  
Pore Size Distribution ◽  
Pore Size ◽  
High Strength ◽  
Curing Time ◽  
Hydration Products ◽  
Resistance Value

The influence of curing time on the mechanical property of the phosphoaluminate cement (PAC) was investigated, and the mechanism was discussed as well. The phase composition and morphology of hydration products, electrical properties, porosity and pore size distribution of PAC cured different age were analyzed with XRD, EIS and MIP. The results showed PAC has the property of early-high strength, and the compressive strength of PAC cured for 1 day was about 70% of 28 days’. The main hydration products of PAC are micro-crystal phase and gel of phosphate and phosphoaluminate which formed compacter microstructure. In addition, there are no calcium hydroxide (CH) and ettringite (AFt) produced during the process of hydration. The compressive strength of PAC increased with age, which was due to more products continuously produced. The ac resistance analysis manifested as the change of the nyquist pattern and resistance value.

Experimental Investigations of Shear Lag Effect in Orthotropic Composite Box Beam

2010 ◽  
Vol 150-151 ◽  
pp. 1750-1753
Author(s):  
Ya Ping Wu ◽  
Yin Hui Wang ◽  
Li Xia Wang ◽  
Zu Guang Bian
Keyword(s):  
Compressive Strength ◽  
High Strength ◽  
Experimental Investigations ◽  
Curing Time ◽  
Hydration Products ◽  
Shear Lag ◽  
Box Beam ◽  
Lag Effect ◽  
Composite Box Beam ◽  
Resistance Value

The influence of curing time on the mechanical property of the phosphoaluminate cement (PAC) was investigated, and the mechanism was discussed as well. The phase composition and morphology of hydration products, electrical properties, porosity and pore size distribution of PAC cured different age were analyzed with XRD, EIS and MIP. The results showed PAC has the property of early-high strength, and the compressive strength of PAC cured for 1 day was about 70% of 28 days’. The main hydration products of PAC are micro-crystal phase and gel of phosphate and phosphoaluminate which formed compacter microstructure. In addition, there are no calcium hydroxide (CH) and ettringite (AFt) produced during the process of hydration. The compressive strength of PAC increased with age, which was due to more products continuously produced. The ac resistance analysis manifested as the change of the nyquist pattern and resistance value.

Effect of CO2 Curing on the Strength of High Strength Pervious Concrete

2020 ◽  
Vol 846 ◽  
pp. 207-212
Author(s):  
Ming Gin Lee ◽  
Yung Chih Wang ◽  
Wan Xuan Xiao ◽  
Ming Ju Lee ◽  
Tuz Yuan Huang
Keyword(s):  
Carbon Dioxide ◽  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
High Strength ◽  
Pervious Concrete ◽  
Control Group ◽  
Curing Time ◽  
Compressive Strength Of Concrete ◽  
Curing Pressure

This study was conducted to assess the effect of CO2 curing on the compressive strength of high strength pervious concrete. The factors studied to evaluate compressive strength of concrete on CO2 curing pressure, curing time, and age of specimen at testing. Three Aggregate sizes, three CO2 curing pressures, three CO2 curing time, and three testing ages were used in this investigation. The research tried to produce a high strength pervious concrete and use carbon dioxide for curing to find out whether it could enhance the compressive strength. The results show that the compressive strength of the control group increases rapidly and its 90-day compressive strength closed to 60 MPa. The 1-day compressive strength has a major impact after CO2 curing and their strength decreased by about 0% to 50% as compared to the control group. However, it is observed that there is only slight difference in relationship between modulus of elasticity and compressive strength obtained from 100 by 200mm cylinders with CO2 curing.

scholarly journals Effects of Environmental Factors on Concrete Carbonation Depth and Compressive Strength

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2167 ◽  
Author(s):  
Ying Chen ◽  
Peng Liu ◽  
Zhiwu Yu
Keyword(s):  
Compressive Strength ◽  
Phase Composition ◽  
Relative Humidity ◽  
Co2 Concentration ◽  
Crystal Structure Analysis ◽  
Hydration Products ◽  
Carbonation Depth ◽  
Concrete Carbonation ◽  
Before And After ◽  
Compressive Strength Of Concrete

The influence of temperature, CO2 concentration and relative humidity on the carbonation depth and compressive strength of concrete was investigated. Meanwhile, phase composition, types of hydration products and microstructure characteristics of samples before and after the carbonation were analyzed by XRD and ESEM. Research results demonstrate that temperature, CO2 concentration and relative humidity influence the carbonation depth and compressive strength of concrete significantly. There is a linear relationship between temperature and carbonation depth, as well as the compressive strength of concrete. CO2 concentration and relative humidity present a power function and a polynomial function with carbonation depth of concrete, respectively. The concrete carbonation depth increases with the increase of relative humidity and reaches the maximum value when the relative humidity is 70%. Significant differences of phase composition, hydration products and microstructure are observed before and after the carbonation. Carbonization products of samples are different with changes of temperatures (10 °C, 20 °C and 30 °C). The result of crystal structure analysis indicates that the carbonation products are mainly polyhedral spherical vaterite and aragonite.

The Preparation of High-Strength and Micropore Lightweight Bauxite Aggregate by In Situ Polymerization and Decomposition

2011 ◽  
Vol 194-196 ◽  
pp. 2135-2139
Author(s):  
Yi Neng Fang ◽  
Hua Zhi Gu ◽  
Yun Sheng Fen ◽  
Lin Jun Wang ◽  
Yan Jing Li
Keyword(s):  
Phase Composition ◽  
Pore Size ◽  
Aluminium Hydroxide ◽  
Average Pore Size ◽  
High Strength ◽  
Organic Polymer ◽  
Low Grade ◽  
Pore Former ◽  
Average Pore

High-strength and micropore lightweight bauxite aggregate was fabricated by low grade raw bauxite powder, aluminium hydroxide powder and organic polymer (OP). OP was used as consolidator, binder and pore former and aluminium hydroxide was used as pore former. The influence of OP and aluminium hydroxide content on the property of the samples was studied. The phase composition and the microstructure of the sintered samples were characterized by XRD, SEM and the pore size distribution was measured by mercury porosimety. The results demonstrate that the bulk density of the samples decreases linearly and the apparent porosity of the samples increases gradually with the addition of OP. The lowest density reached 1.13g/cm3when adding 35% OP and 10% Al(OH)3. The average pore size is around 5μm, and increases with the addition of OP increased. The XRD showed the main phase of the sample is mullite and some little amount of corundum.

Influence of Hipping Pressure on the Strength and the Porosity of Porous Copper

1991 ◽  
Vol 251 ◽  
Author(s):  
Atsushi Takata ◽  
K. Ishizaki ◽  
Y. Kondo ◽  
T. Shioura
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Young’S Modulus ◽  
Open Porosity ◽  
Structural Parameters ◽  
High Strength ◽  
Porous Copper ◽  
Different Temperatures ◽  
Hip Process

ABSTRACTOpen porous copper metals, which have high strength, high open porosity and well controlled pore size distribution, were produced by a hot isostatic press (HIP) process. They were sintered at different temperatures from 973 to 1273K under various HIPping pressures up to 200MPa. Pore size distribution and Young's modulus of the sintered samples were analyzed. The HIPped products have greater strength and higher open porosity than those of the normally sintered ones. The internal structural parameters such as pore size distribution were controlled by changing the HIPping pressure.

Study on Physicochemical Properties of the Carbonated Hydroxyapatite Bone Cement

2007 ◽  
Vol 280-283 ◽  
pp. 1545-1548
Author(s):  
Li Min Dong ◽  
Chen Wang ◽  
Jie Mo Tian ◽  
Jian Pan ◽  
Qing Feng Zan
Keyword(s):  
Compressive Strength ◽  
Phase Composition ◽  
Physicochemical Properties ◽  
Bone Cement ◽  
Pore Size ◽  
Setting Time ◽  
Mineral Phase ◽  
Carbonated Hydroxyapatite ◽  
Natural Bone ◽  
Ft Ir

Carbonated hydroxyapatite (CHA) bone cement is capable of self-setting and has the component similar to the mineral phase of natural bone. But it is compact in structure and short of cavity, which limits new bone growing into CHA bone cement. In this paper, the foaming method was adopted to prepare the porous CHA. The setting time, compressive strength, porosity and pore size of the CHA were examined. The phase composition of the CHA was tested with XRD and FT-IR. The microstructure of the CHA was observed with SEM. The results show that setting time of 7~19 minutes, compressive strength of 26~32MPa, pore size of 100~200µm, porosity of 50~60%.

Microstructure and Porosity of Metakaolin Blended Cements

1988 ◽  
Vol 136 ◽  
Author(s):  
P. Bredy ◽  
M. Chabannet ◽  
J. Pera
Keyword(s):  
Compressive Strength ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Hydrated Cement ◽  
Cement Pastes ◽  
Blended Cements ◽  
Mercury Intrusion ◽  
Pozzolanic Cement

ABSTRACTFive compositions with 10% to 50% metakaolin for cement substitution were studied. The rate of hydration was studied from the compressive strength after up to 6 months of curing and from the hydrates formed (DTA-XRD). The metakaolin addition considerably reduced portlandite content in the hydrated cement and contributed to the formation of hydrated gehlenite which is not present in OPC paste. The microstructure study (SEM) shows that pozzolanic cement pastes were less crystallized than plain pastes. Mercury intrusion was used to measure porosity of hydrated cement pastes. The porosity with blended cements was higher than that with OPC, except for 10 and 20% metakaolin substitution. Evolution of the pore size distribution was studied: the pozzolanic pastes enhance small diameters.

The The Characterization and Modeling the Mechanical Properties of High Strength Concrete (HSC) Modified with Fly Ash (FA)

2020 ◽  
Vol 38 (2A) ◽  
pp. 173-184 ◽  
Author(s):  
Saman M. Kamal ◽  
Jalal A. Saeed ◽  
Ahmed Mohammed
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Curing Time ◽  
Strength Concrete ◽  
Statistical Variation ◽  
Study Results ◽  
Concrete Testing ◽  
Linked Model

One of the main challenges facing Civil Engineering community is to modify cement quantity in the mix design by admixtures to enhance the mechanical properties. According to more than 1000 data from literature, mechanical characteristics of concrete modified with FA were discussed. The statistical variation with modeling were achieved by set of data. The cement was replaced up to 70% with FA (weight of dry cement) and by cube of concrete testing up to 90 days of curing time and different w/c ratio. The compressive strength of concrete varied from 18-67 MPa, while, for modified concrete with FA, compressive strength ranged from 21-94 MPa, tensile strength ranged from 1-9 MPa and flexural strengths ranged from 3 - 10 MPa. The w/c ratio of concrete modified with FA varied from 0.24-0.53, also the FA content varied from 0-50 %. Vipulanandan correlation model was effective by connecting mechanical properties and compare with Hoek-Brown model. The nonlinear model was used to investigate the effect of FA on properties of normal and high strength concrete. Study results presented a worthy correlation between compressive strength and curing time, w/c ratio and FA content. By using the interactive linked (model) for compressive, tensile, and flexural strengths of concrete quantified well as a function of w/c ratio, curing time and FA content by using a nonlinear relationship.

scholarly journals Effect of Temperature on Concrete Carbonation Performance

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Peng Liu ◽  
Ying Chen ◽  
Zhiwu Yu ◽  
Rongling Zhang
Keyword(s):  
Compressive Strength ◽  
Phase Composition ◽  
Strain Curve ◽  
Crystal Form ◽  
Surface Strain ◽  
Effect Of Temperature ◽  
Linear Segment ◽  
Hydration Products ◽  
Carbonation Depth ◽  
Before And After

In this study, the effect of temperature on macroperformance and microcharacteristic of carbonized concrete was investigated. The carbonation depth, compressive strength, and surface strain of concrete under different simulated environments for 28 d were measured. XRD and ESEM-EDS analysis were conducted to present the phase composition, types of hydration products, and microstructure characteristics of samples before and after carbonation. The results showed that the effects of temperature on carbonation depth, strain, and compressive strength were significant. There was a linear relation between temperature and carbonation depth as well as compressive strength of concrete. The effects of environment factors on concrete surface strain after carbonation manifested as the strain value and the slope of linear segment of strain curve. Significant differences of phase composition and hydration products were observed before and after the carbonation, which mainly manifested as attenuation and disappearance of diffraction peaks of hydration products. Temperature affects the crystal form of the carbonation products.

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