Effect of the compounding of an antifoaming agent and a viscosity modifying agent on the frost resistance of mold bag concrete

2021 ◽  
Vol 308 ◽  
pp. 125016
Author(s):  
Feng Yu ◽  
Zongke Lou ◽  
Ningxia Yan
Keyword(s):  
Frost Resistance ◽  
Modifying Agent ◽  
Antifoaming Agent

scholarly journals INFLUENCE OF MODIFYING AGENT WITH HYDROPHOBIZATION EFFECT ON INCREASE OF OPERATIONAL CHARACTERISTICS OF VIBROPRESSED PRODUCTS

2019 ◽  
pp. 8-13
Author(s):  
Л. Сулейманова ◽  
L. Suleymanova ◽  
М. Малюкова ◽  
M. Malyukova ◽  
А. Слепухин ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Frost Resistance ◽  
Front Face ◽  
Concrete Compressive Strength ◽  
Modifying Agent ◽  
Face Area ◽  
Operational Characteristics ◽  
Negative Role ◽  
Geometrical Dimensions

In the article the method of volumetric hydrophobization by insertion of modifying agents with hydrophobization effect directly in concrete mixture on the stage of mixing is considered and the degree of their influence on physics-mathematics properties of vibropressed products which made on technological line with optimal granulometry, water to cement proportion and parameters of forming is estimated, so that the geometrical dimensions of moulded products satisfy required sizes and limits, and appearance of front-face area satisfied A3 category. There was established the increase of operational characteristics of concrete walkway vibropressed slabs when in use of polyfunctional modifying agents with hydrophobization effect – Murasan BWA 17 and SikaPaver AE-2 in 0.5 % cement weight quantity, wherein there was found the increase of compressive strength of slabs on 23 %, frost resistance on 50 cycles and decrease of water absorption up to 45 % which allows increasing the longevity of small-pieces products. Insertion of volumetric modifier-hydrophobisator Akvasil, only with a mono-characteristic to decrease of water absorption, has negative role on strength characteristics of vibropressed products with decrease of concrete compressive strength by 12 %.

Features of radiothermoluminescence of polypropylene and ethylene propylenediene elastomer SKEPT-4044 compositions with nanoscale metal-containing fillers

2020 ◽  
pp. 66-73
Author(s):  
A.M. Magerramov ◽  
◽  
N.I. Kurbanova ◽  
M.N. Bayramov ◽  
N.A. Alimirzoyeva ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Molecular Mobility ◽  
Fe3o4 Nanoparticles ◽  
Low Temperatures ◽  
Frost Resistance ◽  
Relaxation Processes ◽  
Ethylene Propylene ◽  
Temperature Range ◽  
Β Relaxation

Using radiothermoluminescence (RTL), the molecular mobility features in the temperature range of 77-300 K were studied for the polypropylene (PP)/ethylene propylene diene elastomer SKEPT-4044 with NiO, Cu2O and Fe3O4 nanoparticles (NPs) based on ABS-acrylonitrile butadiene or SCS-divinyl styrene matrices. It has been shown that the introduction of nanofillers in PP significantly affects the nature and temperature of γ- and β-relaxation processes, while the region of manifestation of the β-process noticeably shifts to the region of low temperatures. Composites with Cu2O NPs have a higher β-transition temperature Tβ than composites with other NPs. It was found that PP/SKEPT-4044 composites with Cu2O NPs with a dispersion of 11-15 nm and acrylonitrile butadiene thermoplastics have optimal frost resistance compared to other compositions.

Influence of Electro-Surface Properties of Mineral Filler on Frost Resistance of Powder Concretes

2019 ◽  
Vol 775 (10) ◽  
pp. 12-15
Author(s):  
Sh.M. RAKHIMBAEV ◽  
◽  
N.M. TOLYPINA ◽  
A.A. KOSINOVA ◽  
E.N. KHAKHALEVA ◽  
...  
Keyword(s):  
Surface Properties ◽  
Frost Resistance ◽  
Mineral Filler

Cereals frost resistance correlates with an integral indicators of content of low-molecular-weight protective compounds and activity of antioxidant enzymes

2020 ◽  
Vol 2020 (3) ◽  
pp. 71-86
Author(s):  
O. I. Horielova ◽  
◽  
N. I. Ryabchun ◽  
M. A. Shkliarevskyi ◽  
A. M. Reznik ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Superoxide Dismutase ◽  
Antioxidant Enzymes ◽  
Antioxidant System ◽  
Frost Resistance ◽  
Low Molecular Weight ◽  
Guaiacol Peroxidase ◽  
Wheat Seedlings ◽  
Enzymatic Antioxidant ◽  
Adult Plants

Along with specific adaptive reactions, universal defense reactions, in particular activation of antioxidant system, are of great importance for plant survival under cold conditions. We have studied a relationship among the content of low-molecular-weight protective compounds with antioxidant properties (proline, soluble carbohydrates, flavonoids), the activity of antioxidant enzymes (superoxide dismutase, catalase, and guaiacol peroxidase) in seedlings of winter wheat, rye and triticale, and frost resistance of etiolated seedlings and adult plants at tillering stage. It was found that there was a fairly close correlation between the frost resistance of seedlings and adult cereal plants (r = 0,78). It was shown that a pronounced relationship between individual indicators of antioxidant system functioning in unhardened seedlings and their frost resistance was not found. After 6-day hardening of seedlings at 2-4°C, there was a high correlation between the total indicator of the enzymatic antioxidant system (the sum of normalized indicators of superoxide dismutase, peroxidase, and catalase activity) and their frost resistance (r = 0,86), but the correlation coefficient of this index with frost resistance of plants in tillering phase was significantly lower (r = 0,47). At the same time, a high correlation was found between the content of low-molecular-weight protectors in hardened seedlings and frost resistance of tillering adult plants (r = 0.89). The closest correlation was observed between the integral normalized indicator, comprising the sum of normalized values of antioxidant enzymes activity and the content of low-molecular-weight protectors in hardened seedlings, and frost resistance of seedlings (r = 0,94) and plants in tillering phase (r = 0,89). A presence of specific features in the functioning of antioxidant system during cold adaptation of cereal seedlings was established. Rye is characterized by a high content of low-molecular-weight protective compounds; at the same time, increased activity of antioxidant enzymes - superoxide dismutase and catalase - was noted in wheat seedlings. In triticale, depending on the genotype, the values of both enzymatic antioxidant activity and the content of low-molecular-weight protectors varied.

Bestimmung der Dauerhaftigkeit von Hochleistungsbeton mit Hilfe des CDF-Tests / Determination of the durability of high performance concrete by means of CDF-test

1999 ◽  
Vol 5 (1) ◽  
pp. 29-40
Author(s):  
R. Krumbach ◽  
U. Schmelter ◽  
K. Seyfarth
Keyword(s):  
Frost Resistance ◽  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Strength Concrete ◽  
Factors Influencing

Abstract Variable obsen>ations concerning frost resistance of high performance concrete have been made. The question arises which are the decisive factors influencing durability under the action of frost and de-icing salt. The proposed experiments are to be carried out in cooperation with F.A.- Finger - Institute of Bauhaus University Weimar. The aim of this study is to determine possible change of durability of high strength concrete, and to investigate the origin thereof. Measures to reduce the risk of reduced durability have to be found.

Increase of frost resistance capacity of clay roofing tiles with boron waste addition

2021 ◽  
Vol 280 ◽  
pp. 122493
Author(s):  
Angeliki Christogerou ◽  
Paraskevi Lampropoulou ◽  
Efstathios Panagiotopoulos
Keyword(s):  
Frost Resistance

Frost resistance of internal curing concrete with calcined natural zeolite particles

2021 ◽  
Vol 288 ◽  
pp. 123062
Author(s):  
Xuan Zheng ◽  
Jun Zhang ◽  
Xiaoping Ding ◽  
Hewei Chu ◽  
Jiajia Zhang
Keyword(s):  
Frost Resistance ◽  
Natural Zeolite ◽  
Internal Curing

Safety and efficacy of bone-modifying agents among multiple myeloma patients: A retrospective cohort study

2021 ◽  
pp. 107815522199603
Author(s):  
Christina Billias ◽  
Megan Langer ◽  
Sorana Ursu ◽  
Rebecca Schorr
Keyword(s):  
Multiple Myeloma ◽  
Cohort Study ◽  
Zoledronic Acid ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Osteonecrosis Of The Jaw ◽  
Safety And Efficacy ◽  
Modifying Agent ◽  
Skeletal Related Events ◽  
Agent Group

Objective To determine the incidence of skeletal-related events among multiple myeloma patients who received chemotherapy without a bone-modifying agent (zoledronic acid and denosumab) versus those who received chemotherapy with a bone-modifying agent. The secondary objective was to determine the incidence of skeletal-related events in patients without any prior history of skeletal-related events and who were treated with zoledronic acid every four weeks versus those who received zoledronic acid at an extended interval of every twelve weeks. Additional secondary objectives included the incidence of nephrotoxicity, hypocalcemia and osteonecrosis of the jaw in all patients. Methods This institutional review board-approved, retrospective cohort study included patients 18 to 89 years old with a diagnosis of multiple myeloma, who were being treated with chemotherapy between July 1, 2016 and October 31, 2019. Safety and efficacy were assessed through analysis of pertinent data collected: patient demographics, baseline skeletal-related events, development of new skeletal-related events, number and type of bone-modifying agent doses administered, and drug-related toxicities such as nephrotoxicity, hypocalcemia, and osteonecrosis of the jaw. Results A total of 73 patients were included. New skeletal-related events occurred in 12 patients (27%) in the chemotherapy without a bone-modifying agent group and in 5 patients (17%) in the chemotherapy with a bone-modifying agent group (OR = 0.56, 95% CI [0.172–1.8]; P = 0.32). The incidence of skeletal-related events was similar among patients receiving zoledronic acid every four weeks versus every twelve weeks in patients without a prior skeletal-related event (N = 0 vs. N = 2 respectively; P = 0.47). There were no statistically significant differences observed in each of the three secondary safety endpoints: incidence of hypocalcemia, nephrotoxicity and osteonecrosis of the jaw. Conclusion Multiple myeloma patients receiving chemotherapy without a bone-modifying agent had higher rates of skeletal-related events compared to those being treated with chemotherapy and a bonemodifying agent. Our results highlight the benefit of utilizing bonemodifying agents for the prevention of skeletal-related events in all multiple myeloma patients being treated with chemotherapy.

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