Influence of curing temperature on the mechanical properties and microstructure of limestone powder mass concrete

2020 ◽  
Author(s):  
Weizhun Jin ◽  
Linhua Jiang ◽  
Lin Han ◽  
Lei Chen ◽  
Xiancui Yan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Curing Temperature ◽  
Limestone Powder ◽  
Mass Concrete ◽  
Powder Mass

Long-Term Behavior of Low-Heat Cement Concrete under Different Curing Temperatures

2016 ◽  
Vol 723 ◽  
pp. 819-823 ◽  
Author(s):  
Jae Sung Mun ◽  
Keun Hyeok Yang ◽  
Si Jun Kim
Keyword(s):  
Drying Shrinkage ◽  
Curing Temperature ◽  
Limestone Powder ◽  
Partial Replacement ◽  
Mass Concrete ◽  
Test Results ◽  
Long Term Behavior ◽  
Ambient Curing ◽  
Ternary Blended Concrete

The present study is to estimate long-term characteristics of low-heat cement-based ternary blended concrete prepared for reducing hydration heat in mass concrete. 15% modified fly ash and 5% limestone powder were added for partial replacement of the low-heat cement. To achieve the designed compressive strength of 42 MPa, water-to-binder ratios were determined to be 27.5, 30 and 32.5% for ambient curing temperatures of 5, 20 and 40°C, respectively. Test results showed that, with the decrease in curing temperature, the drying shrinkage strains tended to decrease, whereas creep strain increased.

scholarly journals Effect of limestone powder on mechanical properties and microstructure of phosphogypsum

2021 ◽  
Vol 1777 (1) ◽  
pp. 012012
Author(s):  
P F Ma ◽  
S Li ◽  
B J Cheng ◽  
B Y Yu ◽  
Y X Gao
Keyword(s):  
Mechanical Properties ◽  
Limestone Powder

Impact of the Limestone Powder on the Properties of Cement Paste and Mortar

2012 ◽  
Vol 174-177 ◽  
pp. 236-240
Author(s):  
Jing Zhang ◽  
Zhu Li
Keyword(s):  
Mechanical Properties ◽  
Cement Paste ◽  
Experimental Studies ◽  
Water Requirement ◽  
Limestone Powder ◽  
Inert Material ◽  
Normal Concrete ◽  
Significant Negative Effect ◽  
Negative Effect

Experimental studies on the properties of cement paste and mortar with the use of limestone powder were carried out. The results show that the replacement with 10% to 30% limestone powder in cement paste can reduce the water requirement for certain flowability. As an inert material, the use of the limestone powder has significant negative effect on the mechanical properties of mortar. However, strength requirement of normal concrete (mortar) can be reached by reducing the water to cementious material ratio, which makes the use of limestone powder as a replacement of cement possible.

scholarly journals Effects of Nano-CaCO3/Limestone Composite Particles on the Hydration Products and Pore Structure of Cementitious Materials

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Huashan Yang ◽  
Yujun Che
Keyword(s):  
Mechanical Properties ◽  
Pore Structure ◽  
Reaction System ◽  
Cementitious Materials ◽  
Limestone Powder ◽  
Composite Particles ◽  
Gravimetric Analysis ◽  
Hydration Products ◽  
Scanning Calorimetry ◽  
Necked Flask

The agglomeration of nano-CaCO3 (NC) is the largest bottleneck in applications in cementitious materials. If nano-CaCO3 modifies the surface of micron-scale limestone powder (LS), then it will form nano-CaCO3/limestone composite particles (NC/LS). It is known that micron-scale limestone is easily dispersed, and the “dispersion” of NC is governed by that of LS. Therefore, the dispersion of nano-CaCO3 can be improved by the NC/LS in cementitious materials. In this work, the preparation of NC/LS was carried out in a three-necked flask using the Ca(OH)2-H2O-CO2 reaction system. The morphology of NC/LS was observed by a field emission scanning electron microscope (FE-SEM). The effects of NC/LS on the hydration products and pore structure of cementitious materials are proposed. 5% NC/LS was added into cement paste and mortar, and the mechanical properties of the specimens were measured at a certain age. Differential scanning calorimetry (DSC), thermal gravimetric analysis (TG), and backscattered electron imaging (BSE) were conducted on the specimens to investigate the hydration products and pore structure. The properties of specimens with NC/LS were compared to that of control specimens (without NC/LS). The results revealed that NC/LS reduced the porosity and improved the mechanical properties of the cementitious materials.

scholarly journals Mechanical properties of bulk Sylgard 184 and its extension with silicone oil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Moučka ◽  
M. Sedlačík ◽  
J. Osička ◽  
V. Pata
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Ambient Temperature ◽  
Oil Content ◽  
Silicone Oil ◽  
Polymer System ◽  
Industrial Applications ◽  
Curing Temperature ◽  
Rotational Rheometer ◽  
Oil Concentration

AbstractDue to its simple curing and very good mechanical properties, Sylgard 184 belongs to the most widely and frequently used silicones in many industrial applications such as microfluidics and microengineering. On top of that its mechanical properties are further controllable through the curing temperature, which may vary from ambient temperature up to 200 °C; the lower the curing temperature the lower the mechanical properties (Johnston et al. in J Micromech Microeng 24:7, 2014. 10.1088/0960-1317/24/3/035017). However, certain specialised application may require even a softer binder than the low curing temperature allows for. In this study we show that this softening can be achieved with the addition of silicone oil into the Sylgard 184 system. To this end a series of Sylgard 184 samples with varying silicone oil concentrations were prepared and tested (tensile test, rotational rheometer) in order to determine how curing temperature and silicone oil content affect mechanical properties. Curing reaction of the polymer system was found to observe 2nd order kinetics in all cases, regardless the oil concentration used. The results suggest that within the tested concentration range the silicone oil addition can be used to soften commercial silicone Sylgard 184.

scholarly journals Novolac/Phenol-Containing Phthalonitrile Blends: Curing Characteristics and Composite Mechanical Properties

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 126 ◽  
Author(s):  
Hanqi Zhang ◽  
Bing Wang ◽  
Yanna Wang ◽  
Heng Zhou
Keyword(s):  
Mechanical Properties ◽  
Fracture Strain ◽  
Mechanical Test ◽  
Gelation Time ◽  
Mechanical Analysis ◽  
Curing Temperature ◽  
Hydroxyl Group ◽  
Rheological Analysis ◽  
Curing Characteristics ◽  
Ft Ir

The phenol-containing phthalonitrile resin is a kind of self-curing phthalonitrile resin with high-temperature resistance and excellent properties. However, the onefold phthalonitrile resin is unattainable to cured completely, and the brittleness of the cured product is non-negligible. This paper focuses on solving the above problems by blending novolac resin into phenol-containing phthalonitrile. Under the action of abundant hydroxyl group, the initial curing temperature and gelation time at 170 °C decrease by 88 °C and 2820 s, respectively, monitored by DSC and rheological analysis. FT-IR spectra of copolymers showed that the addition of novolac increased the conversion rate of nitrile. When the novolac mass fraction is 10%, the peak of nitrile group disappears, which means the complete reaction. The mechanical test of blends composites shows that the maximum fracture strain of 10 wt% novolac addition is 122% higher than those of neat phthalonitrile composites on account of the introduction of flexible novolac chain segments. The mechanical properties are sensitive to elevated post-cured temperature; this is consistent with the result of morphological investigation using SEM. Finally, the dynamic mechanical analysis indicated that the glass transition temperature heightened with the increase of novolac content and post-curing temperature.

Correlation between Curing Temperature and the Properties of Conductive Composites

2013 ◽  
Vol 750-752 ◽  
pp. 119-122 ◽  
Author(s):  
Xiao Ya Wang ◽  
Zhi Dong Xia ◽  
Zhe Li
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Crosslink Density ◽  
Fracture Morphology ◽  
Curing Temperature ◽  
Tensile Fracture ◽  
Elongation At Break ◽  
Conductive Composites ◽  
The Stability ◽  
Better Than

This study was carried out to discuss the influence of curing temperature on the performance of conductive composites filled with nickel-coated graphite (NCG). The electrical conductivity, crosslink density, mechanical properties and tensile fracture morphology have been investigated. The results indicated that curing temperature had great impact on the electrical conductivity and mechanical properties. Voluem resistivity decreased from 43.1 to 0.08 ohm-cm at 125°C-205°C, and the reason was discussed in light of formation and break of the conductive network in the composites. The stability of SR-NCG cured at 165°C-205°C were also better than those cured at other curing temperature. Besides, tensile strength increased from 2.41 to 7.19Mpa at 125°C-225°C, elongation at break have a 56% increase, and Shore A hardness also incresed from 74 to 82.

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