Heat Liberation of Barium Cements as a Background of their Application in Mass Concrete Structures

2016 ◽  
Vol 871 ◽  
pp. 9-15 ◽  
Author(s):  
Yury Barabanshchikov ◽  
Tatiana Belkina ◽  
Anna Muratova ◽  
Andrii Bieliatynskyi
Keyword(s):  
Initial Period ◽  
Setting Time ◽  
Reference Sample ◽  
Concrete Structures ◽  
Heat Liberation ◽  
Cement Clinker ◽  
Exothermic Effect ◽  
Mass Concrete ◽  
Physical Testing ◽  
Different Content

The article deals with heat liberation of barium cements, which influences the crack formation in mass concrete structures. The results of heat release and physical testing of barium cements with a different content of BaO are presented in this paper. The strength of cement and its setting time will decrease significantly, if the content of BaO in clinker is high (about 47%). This cement is characterized by a low water requirement and heat liberation. Properties of cement with a low content of barium oxide (5.5%) are close to the properties of the standard Portland cement. In this case heat liberation is low in the initial period of hardening, but at the later stage it exceeds the exotherm of a reference sample. A small amount of BaO in cement clinker reduces the exothermic effect and increases the thermal crack resistance of concrete.

The Control Study of Mass Concrete Floor Temperature Crack

2012 ◽  
Vol 446-449 ◽  
pp. 3318-3322
Author(s):  
Wei Tong Guo ◽  
Sheng Na Yang
Keyword(s):  
Temperature Difference ◽  
Setting Time ◽  
Cement Clinker ◽  
Maximum Temperature ◽  
Second Phase ◽  
Mass Concrete ◽  
Concrete Construction ◽  
Control Study ◽  
Temperature Crack

Analysis the factors of mass concrete temperature crack. Combined with the Nan Yang Branch of CUCC cement clinker production line of the second phase of mass concrete construction, it proposed some measures about how to prevent the temperature stress crack of mass concrete due to hydration heat of cement generated temperature difference .By controlling the temperature of the concrete strictly, decreasing the temperature difference between inside and outside, preventing shrinkage joint, reducing the slump loss, delaying setting time, etc. To ensure from the construction maintaining process of mass concrete foundation floor, the tensile strength of concrete is always greater than the maximum temperature tensile stress to prevent temperature cracks appear ensure the quality of mass concrete construction.

The Effect on Cement Mortar and Concrete by Admixture of Spray Drying Absorption Products

1989 ◽  
Vol 178 ◽  
Author(s):  
Kirsten G. Jeppesen
Keyword(s):  
Grain Size ◽  
Fly Ash ◽  
Cement Mortar ◽  
Setting Time ◽  
Mineralogical Composition ◽  
Cement Clinker ◽  
Strength Development ◽  
Fall Meeting ◽  
Freeze Thaw ◽  
Spray Dried

AbstractSpray dried absorption products (SDA) having special characteristics are used as substitutes for cement in the preparation of mortars; the qualities of the resulting mixed mortars are described. Conditions are described for mortar mixes, data for which were presented at the MRS Fall Meeting 1987.The influence of the composition of the SDA on water requirement and setting time has been studied. A full scale project involving 3 precast, reinforced concrete front-elements containing 20 and 30 wt.% SDA is described. Strength development, mineralogical composition and corrosion were monitored for two years.A non-standard freeze-thaw experiment was performed which compares mortars containing SDA and fly ash (FA) and also shows the effect of superplasticizer.The possibility of improving the SDA by grinding has been tested and a limited improvement has been found. The strength of the mixed mortars seems slightly influenced by the grain size of SDAGypsum (CaSO4·2H2O), synthetic calcium-sulphite (CaSO3·½H2O) and 2 SDAs have been used as retarders for cement clinker. Mortar test prisms have been cast and comparative strengths after curing for 3 years are reported

Temperature Control and Anti-Cracking Measures for a High-Performance Concrete Aqueduct

2013 ◽  
Vol 405-408 ◽  
pp. 2739-2742 ◽  
Author(s):  
Zhen Hong Wang ◽  
Shu Ping Yu ◽  
Yi Liu
Keyword(s):  
Temperature Control ◽  
Temperature Difference ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Structures ◽  
Apparent Temperature ◽  
Mass Concrete ◽  
Water Pipe ◽  
Thin Walled ◽  
Water Pipe Cooling

To solve the problem of cracks developing on thin-walled concrete structures during construction, the authors expound on the causes of cracks and the crack mechanism. The difference between external and internal temperatures, basic temperature difference and constraints are the main reasons of crack development on thin-walled concrete structures. Measures such as optimizing concrete mixing ratio, improving construction technology, and reducing temperature difference can prevent thin-walled concrete structures from cracking. Moreover, water-pipe cooling technology commonly used in mass concrete can be applied to thin-walled concrete structures to reduce temperature difference. This method is undoubtedly a breakthrough in anti-cracking technology for thin-walled concrete structures, particularly for thin-walled high-performance concrete structures. In addition, a three-dimensional finite element method is adopted to simulate the calculation of temperature control and anti-cracking effects f. Results show the apparent temperature controlling effect of water-pipe cooling for thin-walled concrete structures.

scholarly journals Application areas of phosphogypsum in production of mineral binders and composites based on them: a review of research results

2018 ◽  
Vol 149 ◽  
pp. 01012 ◽  
Author(s):  
Leonid Dvorkin ◽  
Nataliya Lushnikova ◽  
Mohammed Sonebi
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Industrial Wastes ◽  
Cement Clinker ◽  
Complete Replacement ◽  
Slaked Lime ◽  
The Impact ◽  
Furnace Slag

The increase of the consumption of gypsum products in construction industry with a limited amount of natural gypsum deposits requires alternative sources of gypsum-containing raw materials. In some countries which have fertilizers industry plants, the problem can be solved using industrial wastes, e.g. phosphorgypsum – a byproduct of fertilizers’ production. Kept in dumps over decades, phosphorgypsum is subjected to the chemical changes due to washing out impurities with rain and other natural factors. However, there are observed deviations of harmful impurities in dumped PG depending on its age., Phosphorgypsum of any age requires chemical treatment to neutralize remains of phosphorus and sulfuric acids, fluorine compounds. According to our researches one of the most simple and effective method of neutralization the impurities is using lime-containing admixtures. The paper presents results of laboratory tests of phosphorgypsum as a component of clinker and non-clinker binders. There were investigated the impact of phosphorgypsum as admixture for clinker binders to substitute natural gypsum. Neutralized phosphorgypsum can be applied as mineralizing admixture in calcination of Portland cement clinker. Adding 2 to 2.5% of phosphorgypsum as setting time regulator resulted in a similar physical and mechanical properties compared to mix made with natural gypsum. Another important area of phosphorgypsum application is sulphate activatoion of low-clinker blast-furnace slag cement (clinker content is less than 19%). According to results, the incorporation of phosphorgypsum as sulphate activator in cement has the better effect as natural gypsum. Other development has been carried out to modify the phosphorgypsum binder properties. Complex additive consisted of polycarboxylate-based superplasticizer and slaked lime permitted an increase mechanical properties of hardened phosphorgypsum binder due to significant a reduction of water consumption. Such modified binder can be used as partial or complete replacement of gypsum binder for filling cements and finishing plasters. It can substitute gypsum in non-clinker binders like supersulphated cements. There were also developed compositions of supersulphated cements based on low-alumina blast furnace slag and phosphorgypsum. Supersulphated cements were tested in normal-weight and light-weight concrete.

scholarly journals Optimization of an Eco-Friendly Hydraulic Road Binders Comprising Clayey Dam Sediments and Ground Granulated Blast-Furnace Slag

Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 443
Author(s):  
Selma Bellara ◽  
Mustapha Hidjeb ◽  
Walid Maherzi ◽  
Salim Mezazigh ◽  
Ahmed Senouci
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Road Construction ◽  
Cement Clinker ◽  
Partial Replacement ◽  
Industry Waste ◽  
Impact Reduction ◽  
Compressive And Flexural Strengths ◽  
Furnace Slag

This study investigated the potential use of Zerdezas dam Calcined Sediments (CS) and El-Hadjar Blast Furnace Slag (GGBS) from northern Algeria as a partial replacement of cement (C) in normal hardening hydraulic road binders. Two binder mix designs were optimized using a Response Surface Methodology (RSM). The first mix, 50C35GGBS15CS, consisted of 50% cement, 35% blast furnace slag, and 15% calcined sediment. The second mix, 80C10GGBS10CS, consisted of 80% cement, 10% blast furnace slag, and 10% calcined sediments. The tests of workability, setting time, volume expansion, compressive and flexural strengths, porosity, and SEM were conducted to ensure that both mixes meet the standard requirements for road construction binders. The two proposed mixes were qualified as normal hardening hydraulic road binder. The reuse of the sediments will contribute to a better disposal of dam sediments and steel industry waste and to preserve natural resources that are used for manufacturing cement. It will also contribute to the environmental impact reduction of cement clinker production by reducing greenhouse gas emissions.

Comparison of thermal cracking potential evaluation criteria for mass concrete structures

2021 ◽  
Vol 54 (6) ◽  
Author(s):  
Jianda Xin ◽  
Yi Liu ◽  
Guoxin Zhang ◽  
Zhenhong Wang ◽  
Ning Yang ◽  
...  
Keyword(s):  
Evaluation Criteria ◽  
Concrete Structures ◽  
Thermal Cracking ◽  
Mass Concrete ◽  
Cracking Potential ◽  
Potential Evaluation
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