Effect of Cement Content and Curing Period on Properties of DUT-1 Synthetic Model Ice

2003 ◽  
Vol 125 (4) ◽  
pp. 288-292 ◽  
Author(s):  
Zhijun Li ◽  
Yongxue Wang ◽  
Xiwen Wang ◽  
Guangwei Li

The effects of cement content and curing period on a new synthetic model ice, DUT-1, are reported. The cement (450#) contents were 10%, 11%, 12%, 13%, 14%, 15% and 16% by dry weight of mixture material. Eight different curing periods were used: 66 h, 92 h, 115 h, 139 h, 163 h, 186 h, 211 h and 235 h. Physical and mechanical properties, such as density, compressive strength, flexural strength, and elastic modulus, were determined. The density and mechanical parameters were found to increase with increasing cement content, whereas the durations of curing period under normal air temperature resulted in increasing these properties to a maximum value, then decreasing values.

Author(s):  
Zhijun Li ◽  
Yongxue Wang ◽  
Xiwen Wang ◽  
Guangwei Li

The effect of cement content and curing period on a new kind of synthetic model ice, DUT–1 synthetic model ice is reported. The 450# cement contents were 10%, 11%, 12%, 13%, 14%, 15% and 16% by dry weight of mixture materials. Eight different curing periods were used: 66h, 92h, 115h, 139h, 163h, 186h, 211h and 235h. Physical and mechanical properties such as density, compressive strength, flexural strength, elastic modulus were determined. The cement content was found to increase the density and mechanical parameters with content increasing, whereas curing periods exhibited increasing these parameters to a top value, then decreasing under normal air temperature curing.


Author(s):  
Haopeng Jiang ◽  
Annan Jiang ◽  
Fengrui Zhang

Experimental tests were conducted to study the influence of natural cooling and water cooling on the physical and mechanical properties of quartz sandstone. This study aims to understand the effect of different cooling methods on the physical and mechanical properties of quartz sandstone (such as mass, volume, density, P-wave velocity, elastic modulus, uniaxial compressive strength, etc.). The results show that the uniaxial compressive strength (UCS) and elastic modulus(E) of the specimens cooled by natural-cooling and water-cooling decrease with heating temperature. At 800℃, after natural cooling and water cooling, the average value of UCS decreased by 34.65% and 57.90%, and the average value of E decreased by 87.66% and 89.05%, respectively. Meanwhile, scanning electron microscope (SEM) images were used to capture the development of microcracks and pores within the specimens after natural-cooling and water-cooling, and it was found that at the same temperature, water cooling treatment was more likely to cause microcracks and pores, which can cause more serious damage to the quartz sandstone. These results confirm that different cooling methods have different effects on the physical and mechanical properties of quartz sandstone, and provide a basis for the stability prediction of rock mass engineering such as tunnel suffering from fire.


Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1662 ◽  
Author(s):  
Jianguo Wang ◽  
Bowen Hu ◽  
Jia Hwei Soon

The variation of physical and mechanical properties of the lightweight bulk filling material with cement and expanded polystyrene (EPS) beads contents under different confining pressures is important to construction and geotechnical applications. In this study, a lightweight bulk filling material was firstly fabricated with Singapore marine clay, ordinary Portland cement and EPS. Then, the influences of EPS beads content, cement content, curing time and confining pressure on the mass density, stress–strain behavior and compressive strength of this lightweight bulk filling material were investigated by unconsolidated and undrained (UU) triaxial tests. In these tests, the mass ratios of EPS beads to dry clay (E/S) were 0%, 0.5%, 1%, 2%, and 4% and the mass ratios of cement to dry clay (C/S) were 10% and 15%. Thirdly, a series of UU triaxial tests were performed at a confining pressure of 0 kPa, 50 kPa, 100 kPa, and 150 kPa after three curing days, seven curing days, and 28 curing days. The results show that the mass density of this lightweight bulk filling material was mainly controlled by the E/S ratio. Its mass density decreased by 55.6% for the C/S ratio 10% and 54.9% for the C/S ratio 15% when the E/S ratio increased from 0% to 4% after three curing days. Shear failure more easily occurred in the specimens with higher cement content and lower confining pressure. The relationships between compressive strength and mass density or failure strain could be quantified by the power function. Increasing cement content and reducing EPS beads content will increase mass density and compressive strength of this lightweight bulk filling material. The compressive strength with curing time can be expressed by a logarithmic function with fitting correlation coefficient ranging from 0.83 to 0.97 for five confining pressures. These empirical formulae will be useful for the estimation of physical and mechanical properties of lightweight concretes in engineering application.


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Ji-jing Wang ◽  
Zhen-ning Shi ◽  
Ling Zeng ◽  
Shuang-xing Qi

In order to analyze the influence of different nanoadditives on the physical and mechanical properties of similar silty mudstone materials, nano-TiO2 (NTi), nano Al2O3 (NAl), and nanobentonite (NBe) were added to improve the physical and mechanical properties of silty mudstone similar materials. The physical and mechanical parameters are more in line with silty rock. Finally, nanometer additives suitable for silty mudstone similar materials are determined by conducting density test, natural water absorption test, uniaxial compression test, splitting test, softening coefficient test, expansibility test, and microscopic test. The effects of adding NTi, NAl, and NBe on improving the physical and mechanical properties of silty mudstone similar materials were studied to analyze the influence law of different NTi, NAl, and NBe contents on similar material density, natural water absorption, uniaxial compressive strength, tensile strength, softening coefficient, expansion rate, and other physical and mechanical parameters. The microscopic morphology of similar materials was analyzed by scanning electron microscopy and the mechanism of influence of nanoadditives on the microscopic structure of samples was revealed. The results are as follows. (1) The density of similar materials of silty mudstone increases with the increase of the content of nanoadditive. The natural water absorption rate decreased first and then increased with the increase of the content of nanometer additives, while the softening coefficient decreased with the increase of the content of nanometer additives. The uniaxial compressive strength and tensile strength increased first and then decreased with the increase of the content of nanometer additives. This is due to the incorporation of the nanoadditive amount effective to promote the hydration reaction of gypsum and accelerate the production of cement, while a similar material may be filled in the pores, reducing the internal defects, a similar material to make denser; when excessive dosage, nanoadditives agglomeration occurs, resulting in deterioration of the effect, but will reduce the mechanical properties of similar materials. (2) When the content of NBe is 6%, the physical and mechanical parameters of similar materials can reach or be closer to the silty raw rock except uniaxial compressive strength. The failure mode of the uniaxial compression specimen is also the same as that of the original rock, which can be used as the best choice. The research results laid the foundation for further analysis of NBe application in similar materials.


2019 ◽  
Vol 106 ◽  
pp. 77-84
Author(s):  
WERONIKA FILIPIAK ◽  
GRZEGORZ KOWALUK

Selected physical and mechanical properties of high-density wet formed fibreboards produced with different cement content. The aim of this work was to produce, in laboratory conditions, high-density wet formed fibreboards with a different cement binder content: 0%; 0.5%; 1%; 2%; 5%; 10%. The panels were tested for their physical and mechanical properties in order to determine the effect of added cement on the properties of the boards. The results show that the mechanical parameters of the tested panels grow compare to the reference panel when the mass share of cement is 0.5%, and decreases with the cement share increase to 10%. The remaining physical parameters of the tested panels get worse with the cement content increase.


2014 ◽  
Vol 608 ◽  
pp. 41-46
Author(s):  
Soravich Mulinta

The objective of this study is to investigate the effect of red clay, grog and cement content (5,10,15,20%) on unfired clay brick’s properties. The comparative properties of construction bricks produced by the community fulfilled the requirements of Thai industrial standard (TIS 77-2545) for brick processing in Small and Micro Community Enterprise of Clay Brick Making Group in Son Bun Reung village. The physical and mechanical properties were tested consisting of the volume shrinkage, bulk density, appearance porosity, moisture expansion, slaking, compressive and fractural strength. The result showed that physical-mechanical properties were improved by the addition of cement. The unfired clay brick consisting of 100% grog and 20% cement had 4.5% shrinkage value. The bulk density and appearance porosity were 1.77 g/cm2 and 3.5%, respectively. The fractural strength of unfired clay bricks was 41.2 kg/cm2. The compressive strength of unfired clay bricks was 282.4 kg/cm2. The clay bricks were not slaking.


2018 ◽  
Vol 931 ◽  
pp. 475-480 ◽  
Author(s):  
Nikolay V. Lyubomirskiy ◽  
Stanisław Fic ◽  
Sergey I. Fedorkin

A technique for determining the modulus of elasticity of сonstruction materials on samples of small dimensions has been developed. Physical and mechanical properties of building materials based on calcareous-lime compositions of semi-dry pressing, hardening according to the principle of forced carbonization, depending on the prescription and technological factors of their production have been studied. It has been demonstrated that on the basis of these materials it is possible to obtain building products with compressive strength up to 30 MPa, tensile strength at bending up to 5 MPa and higher, and an elastic modulus up to 18 GPa.


2012 ◽  
Vol 616-618 ◽  
pp. 346-349 ◽  
Author(s):  
Yan Hua Guo ◽  
Rui Jun Cao ◽  
Li Hua Zhu

The similar material composed of quartz sand, gypsum, colophony and alcohol solution, model test and similarity theory were depended on in the test, and standard cylinder specimens were made in different proportions. The physical and mechanical properties of blocks were studied through uniaxial compressive experiments. The researches show that the ratio of elastic modulus and down modulus of the specimens increase linearly with the increase of the ratio of sand and cement; while the elastic modulus, the down modulus and the uniaxial compressive strength decrease in shah model of index function with the increase of it. All parameters mentioned above reduce rapidly with the increase of the ratio of sand and cement when the ratio of sand and cement less than 4, if not, the parameters increase slowly.


2012 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Djoko Purwanto

Timber Acacia mangium (Acacia mangium, Willd) for Furniture. The study aims to determine the mechanical and physical properties and the decorative value (color and fiber) wood of acacia mangium with using finishing materials. This type of finishing material used is ultran lasur natural dof ,ultran lasur classic teak, aqua politur clear dof, aqua politur akasia dan aqua politur cherry. After finishing the wood is stored for 3 months. Test parameters were observed, namely, physical and mechanical properties of wood, adhesion of finishing materials, color and appearance of the fiber, and timber dimensions expansion. The results showed that the mechanical physical properties of acacia wood qualified SNI. 01-0608-89 about the physical and mechanical properties of wood for furniture, air dry the moisture content from 13.78 to 14.89%, flexural strength from 509.25 to 680.50 kg/cm2, and compressive strength parallel to fiber 342.1 - 412.9 kg/cm2. Finishing the treatment process using five types of finishing materials can increase the decorative value (color and fiber) wood. Before finishing the process of acacia mangium wood has the appearance of colors and fibers and less attractive (scale scores 2-3), after finishing acacia wood fibers have the appearance of colors and interesting and very interesting (scale 4-5).Keywords: mangium wood, mechanical properties, decorative value, finishing, furniture.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2303
Author(s):  
Congyu Zhong ◽  
Liwen Cao ◽  
Jishi Geng ◽  
Zhihao Jiang ◽  
Shuai Zhang

Because of its weak cementation and abundant pores and cracks, it is difficult to obtain suitable samples of tectonic coal to test its mechanical properties. Therefore, the research and development of coalbed methane drilling and mining technology are restricted. In this study, tectonic coal samples are remodeled with different particle sizes to test the mechanical parameters and loading resistivity. The research results show that the particle size and gradation of tectonic coal significantly impact its uniaxial compressive strength and elastic modulus and affect changes in resistivity. As the converted particle size increases, the uniaxial compressive strength and elastic modulus decrease first and then tend to remain unchanged. The strength of the single-particle gradation coal sample decreases from 0.867 to 0.433 MPa and the elastic modulus decreases from 59.28 to 41.63 MPa with increasing particle size. The change in resistivity of the coal sample increases with increasing particle size, and the degree of resistivity variation decreases during the coal sample failure stage. In composite-particle gradation, the proportion of fine particles in the tectonic coal sample increases from 33% to 80%. Its strength and elastic modulus increase from 0.996 to 1.31 MPa and 83.96 to 125.4 MPa, respectively, and the resistivity change degree decreases. The proportion of medium particles or coarse particles increases, and the sample strength, elastic modulus, and resistivity changes all decrease.


Sign in / Sign up

Export Citation Format

Share Document