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 ◽  
...  
Author(s):  
Aravind Tankasala ◽  
Anton K. Schindler ◽  
Kyle A. Riding

This paper describes the results of a numerical investigation of incorporating lightweight aggregate (LWA) in mass concrete structures. Numerical simulation was performed with ConcreteWorks software on three rectangular piers for normal weight concrete, internally cured concrete, sand–lightweight concrete, and all–lightweight concrete. Results show that temperature differences greater than 35°F may not necessarily introduce thermal cracking in mass concrete made with LWA. Maximum core temperatures and temperature differences increased with decreasing concrete density; however, the cracking risk of the mass concrete elements decreased as a greater quantity of LWA was used, regardless of element size. This trend occurred because other properties, such as coefficient of thermal expansion, creep, modulus of elasticity, tensile strength, and geometrical conditions, influenced the risk of thermal cracking. Additionally, the identification of the cross-section locations involved in measuring the critical temperature difference in a mass concrete structure are presented. The results of this work can be helpful in identifying critical stress locations in cross sections and assessing the cracking risk for mass concrete structures. A temperature and stress analysis is recommended before mass concrete construction involving LWA is begun.


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2019 ◽  
Author(s):  
Ryoichi Ashizawa ◽  
◽  
Toshiaki Mizobuchi ◽  
Hiroki Izumi ◽  
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...  

Author(s):  
Andrew Z. Boeckmann ◽  
Zakaria El-tayash ◽  
J. Erik Loehr

Some U.S. transportation agencies have recently applied mass concrete provisions to drilled shafts, imposing limits on maximum temperatures and maximum temperature differentials. On one hand, temperatures commonly observed in large-diameter drilled shafts have been observed to cause delayed ettringite formation (DEF) and thermal cracking in above-ground concrete elements. On the other, the reinforcement and confinement unique to drilled shafts should provide resistance to thermal cracking, and the provisions that have been applied are based on dated practices for above-ground concrete. This paper establishes a rational procedure for design of drilled shafts for durability requirements in response to hydration temperatures, which addresses both DEF and thermal cracking. DEF is addressed through maximum temperature differential limitations that are based on concrete mix design parameters. Thermal cracking is addressed through calculations that explicitly consider the thermo-mechanical response of concrete for predicted temperatures. Results from application of the procedure indicate consideration of DEF and thermal cracking potential for drilled shafts is prudent, but provisions that have been applied to date are overly restrictive in many circumstances, particularly the commonly adopted 35°F maximum temperature differential provision.


2013 ◽  
Vol 405-408 ◽  
pp. 2739-2742 ◽  
Author(s):  
Zhen Hong Wang ◽  
Shu Ping Yu ◽  
Yi Liu

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.


Vestnik MGSU ◽  
2020 ◽  
pp. 380-398
Author(s):  
Nikolay A. Aniskin ◽  
Nguyen Trong Chuc

Introduction. The concreting of solid structures, such as concrete dams, bridge constructions, foundations of buildings and structures, is accompanied by exothermic heating, caused by cement hydration. Heat, emitted by mass concrete blocks, slowly leaves constructions. A substantial temperature difference frequently arises between the solid concrete centre and its surface. If this temperature difference reaches a critical value, thermal cracking occurs, which destroys structural continuity. Temperature problems and those associated with thermal stress state should be resolved to pre-assess and prevent potential cracking. This problem has enjoyed the attention of specialists, and it has been the subject of numerous research projects. Materials and methods. The overview is based on the information about implemented research projects focused on the thermal cracking of mass concrete dams and its prevention. Computer modeling techniques were applied to develop a mathematical model capable of projecting and assessing the potential cracking of mass concrete. Results. The co-authors have compiled an overview of advanced approaches to the assessment of potential thermal crack formation, contemporary problem-solving methods and selected research findings obtained using the finite element method. The co-authors offer a thermal behaviour/thermal stress state projection methodology for solid concrete, as well as a thermal crack formation assessment methodology. Conclusions. The thermal cracking problem has not been solved yet. The proposed methodology and a projection-oriented numerical model can be used as a reference by civil engineers in the process of designing and constructing concrete gravity dams. It may help to reduce cracking probability caused by heat evolution in cement.


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