Cross-scale Study on the Mechanical Properties and Frost Resistance Durability of Aeolian Sand Concrete

Using waste to produce a new type of air entraining agent (AEA), carrying out research of the concrete’s mixture performance, mechanical properties and frost resistance durability after mixing with the AEA, with results showing that amount of air entrained in the concrete mixture and the water reducing rate increases along with the increase of the addition of the new AEA, and its compressive strength loss laws are similar with that of normal AEAs. During the frost-thaw cycle test, when the weight loss rate has reached its limit, concrete with the new AEA added can withstand almost 300 cycles, and at this time the relative dynamic modulus of the concrete, when the amount of air entrained in it is 4.5%, is 83.5%, and the relative dynamic modulus is 85.4% when the amount of air entrained is 5.3%. The addition of the AEA has obviously improved the pore structure of the concrete, and significantly raising its frost resistance durability.

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Study on Durability and Pore Characteristics of Concrete under Salt Freezing Environment

Materials ◽

10.3390/ma14237228 ◽

2021 ◽

Vol 14 (23) ◽

pp. 7228

Author(s):

Xinchao Zheng ◽

Fang Liu ◽

Tao Luo ◽

Yanfu Duan ◽

Yu Yi ◽

...

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Frost Resistance ◽

Three Dimensional ◽

Clean Water ◽

Two Dimensional ◽

Nacl Solution ◽

Freezing And Thawing ◽

Pore Characteristics ◽

Resistance Durability

The macroscopic mechanical properties and frost resistance durability of concrete are closely related to the changes in the internal pore structure. In this study, the two-dimensional and three-dimensional ICT (Industrial Computerized Tomography) pore characteristics of C30 concrete specimens before and after freezing and thawing in clean water, 5 wt.% NaCl, 5 wt.% CaCl2, and 5 wt.% CH3COOK solution environments are obtained through concrete frost resistance durability test and ICT scanning technology. The effects of pore structure changes on concrete frost resistance, durability, and compressive strength mechanical properties after freezing and thawing cycles in different salt solution environments are analyzed. This paper provides new means and ideas for the study of concrete pores. The results show that with the increase in the freezing and thawing times, the concrete porosity, two-dimensional pore area, three-dimensional pore volume, and pore number generally increase in any solution environment, resulting in the loss of concrete compressive strength, mortar spalling, and the decrease in the relative dynamic elastic modulus. Among them, the CH3COOK solution has the least influence on the concrete pore changes; the NaCl solution has the greatest influence on the change in the concrete internal porosity. The damage of CaCl2 solution to concrete is second only to the NaCl solution, followed by clean water. The increase in the concrete internal porosity from high to low is NaCl, CaCl2, clean water, and CH3COOK. The change in the pore volume of 0.1 to 1 mm3 after the freeze–thaw cycle is the main factor for reducing concrete strength. The test results have certain guiding value for the selection of deicing salt in engineering.

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Study on the Mechanical Properties and Frost Resistance of Recycled Concrete Prepared by Village Construction Wastes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.418-420.406 ◽

2011 ◽

Vol 418-420 ◽

pp. 406-410

Author(s):

Jun Liu ◽

Yao Li ◽

Dan Dan Hong ◽

Yu Liu

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Frost Resistance ◽

Cement Mortar ◽

Strength Loss ◽

Recycled Concrete ◽

Recycled Aggregate ◽

Replacement Rate ◽

Concrete Mechanical Properties ◽

Better Than

Abstract. Recycled aggregate—rural building material wastes pretreated by cement mortar—are applied into concrete with different replacement rates: 0, 25%, 50%, 75%, and 100%. Results from measurements of compressive strength, cleavage tensile strength, mass loss after fast freeze-thaw cycles, and compressive strength loss indicate that a different recycled aggregate replacement rate certainly influences concrete mechanical properties and frost resistance. Recycled aggregate replacement rates less than 75% performs better than common concrete. Data from the 100% replacement rate is worse than that of rates less than 75% but still satisfy the general demands of GB standard on C30 concrete.

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The workability, porosity characteristics, frost resistance, durability coefficient and compressive strength of SCC incorporating different type of admixtures

Underground Infrastructure of Urban Areas 2 ◽

10.1201/b15453-14 ◽

2011 ◽

pp. 110-117

Author(s):

B Łaźniewska-Piekarczyk

Keyword(s):

Compressive Strength ◽

Frost Resistance ◽

Resistance Durability

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Modyfikowanie HTPB (α,ω-dihydroksypolibutadienu) w reakcjach estryfikacji, silanizacji, epoksydacji i uwodornienia

Materiały Wysokoenergetyczne / High Energy Materials ◽

10.22211/matwys/0168 ◽

2018 ◽

pp. 30-45

Author(s):

Michał Chmielarek ◽

Paweł Maksimowski ◽

Tomasz Gołofit ◽

Katarzyna Cieślak ◽

Wojciech Pawłowski ◽

...

Keyword(s):

Mechanical Properties ◽

Low Temperatures ◽

Frost Resistance ◽

High Energy ◽

Insulating Materials ◽

Rocket Propulsion ◽

Materials Research ◽

Selection Of

HTPB is a valuable comonomer for the preparation of polyurethanes. Thanks to its specific properties, it gives these materials frost resistance and excellent mechanical properties, especially at low temperatures. The polyurethanes thus obtained are used in the production of propellants used in space and military rocket propulsion, and are the basis for frost-resistant adhesives and insulating materials. Research on the selection of binder indicates the use of high energy polymers or modifications of previously used polymers improving their properties. The results of research on ways of changing the properties of HTPB through its modification and thus an increase of application possibilities will be presented.

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Influential Factors in Transportation and Mechanical Properties of Aeolian Sand-Based Cemented Filling Material

Minerals ◽

10.3390/min9020116 ◽

2019 ◽

Vol 9 (2) ◽

pp. 116 ◽

Cited By ~ 3

Author(s):

Nan Zhou ◽

Haobin Ma ◽

Shenyang Ouyang ◽

Deon Germain ◽

Tao Hou

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Cement Content ◽

Ash Content ◽

Influential Factors ◽

Filling Material ◽

Aeolian Sand ◽

Early Hydration ◽

Filling Materials ◽

Slag Content

Given that normal filling technology generally cannot be used for mining in the western part of China, as it has only a few sources for filling gangue, the feasibility of instead using cemented filling materials with aeolian sand as the aggregate is discussed in this study. We used laboratory tests to study how the fly ash (FA) content, cement content, lime–slag (LS) content, and concentration influence the transportation and mechanical properties of aeolian-sand-based cemented filling material. The internal microstructures and distributions of the elements in filled objects for curing times of 3 and 7 days are analyzed using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The experimental results show that: (i) the bleeding rate and slump of the filling-material slurry decrease gradually as the fly ash content, cement content, lime–slag content, and concentration increase, (ii) while the mechanical properties of the filled object increase. The optimal proportions for the aeolian sand-based cemented filling material include a concentration of 76%, a fly ash content of 47.5%, a cement content of 12.5%, a lime–slag content of 5%, and an aeolian sand content of 35%. The SEM observations show that the needle/rod-like ettringite (AFt) and amorphous and flocculent tobermorite (C-S-H) gel are the main early hydration products of a filled object with the above specific proportions. After increasing the curing time from 3 to 7 days, the AFt content decreases gradually, while the C-S-H content and the compactness increase.

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Influence of Restrained Condition on Mechanical Properties, Frost Resistance, and Carbonation Resistance of Expansive Concrete

Materials ◽

10.3390/ma13092136 ◽

2020 ◽

Vol 13 (9) ◽

pp. 2136

Author(s):

Nguyen Duc Van ◽

Emika Kuroiwa ◽

Jihoon Kim ◽

Hyeonggil Choi ◽

Yukio Hama

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Frost Resistance ◽

Total Porosity ◽

Length Change ◽

Ratio Test ◽

Expansive Concrete ◽

Restrained Condition ◽

Carbonation Resistance ◽

Compressive Strength Test

This paper presents the results of an experimental investigation of the effect of the restrained condition on the mechanical properties, frost resistance, and carbonation resistance of expansive concrete with different water–binder ratios. In this study, length change ratio test, expansion strain test, compressive strength test, mercury intrusion porosimetry test, underwater weighing test, freezing–thawing test, and accelerated carbonation test were performed to evaluate the mechanical properties, pore size distribution, total porosity, and durability of expansive concrete under both restrained and unrestrained conditions. The test results indicate that the length change ratio and expansion strain of the expansive concrete were controlled by the restrained condition. The compressive strength of expansive concrete was enhanced by the triaxial restraining when the amount of expansive additive was 40 kg/m3 of concrete. Two hypotheses were described to explain the change of pore structure change expansive mortar. The results also indicate that the carbonation resistance and frost resistance were improved by the uniaxial restrained condition. Furthermore, the effect of the restrained condition must be considered to evaluate not only the experimental results of the expansive concrete with a high EX replacement level but also the expansive concrete combining other cement replacement materials.

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Research of Influence of Plasticizers on the Low-Temperature and Mechanical Properties of Rubbers

Materials Science Forum ◽

10.4028/www.scientific.net/msf.945.459 ◽

2019 ◽

Vol 945 ◽

pp. 459-464 ◽

Cited By ~ 1

Author(s):

M.D. Sokolova ◽

A.F. Fedorova ◽

V.V. Pavlova

Keyword(s):

Mechanical Properties ◽

Low Temperature ◽

Frost Resistance ◽

Nitrile Rubber ◽

Butadiene Nitrile Rubber

In this paper, influence of new plasticizers on the mechanical and low-temperature properties of rubbers is studied. The subjects of the research are rubbers based on BNKS-18 butadiene-nitrile rubber and Hydrin T-6000 epichlorohydrin rubber (ECHR). As used plasticizers: DINP (diisononylphthalate), TOTM (trioctyltrimellitate), DOA (dioctyladipate), Alphaplast (complex plasticizer based on esters of organic alcohols and acids). For identification the efficiency, rubbers with the studied plasticizers compared with standard rubber, in which plasticizers have not introduced, as well as with rubber in which a widely used industrial plasticizer DOF (dioktilphthalate) was added. Research of the mechanical properties of rubbers based on BNKS-18 showed that the introduction of plasticizers leads to an increase in elasticity and a slight decrease in the strength of rubbers and on the contrary for rubbers based on ECHR. Low-temperature properties of rubbers with all studied plasticizers have an increased level in comparison with standard rubber. In rubber based on BNKS-18, the highest values of the coefficient of frost resistance at-45°C are observed with the introduction of plasticizers Alphaplast and DOA, an increase in the index compared to standard rubber is more than 50%. The same plasticizers have shown the greatest contribution to the increase in frost resistance of rubbers based on ECHR.

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