Numerical Analysis of Lining Temperature Field of Hydraulic Tunnel under the Highway

2010 ◽  
Vol 163-167 ◽  
pp. 1505-1509
Author(s):  
Xiao Yun Jia ◽  
Bao Long Lin
Keyword(s):  
Temperature Field ◽  
Numerical Analysis ◽  
Structural Characteristics ◽  
Crack Control ◽  
Temperature Changes ◽  
Finite Element Software ◽  
Concrete Crack ◽  
Geological Conditions ◽  
North Water ◽  
The Difference

Based on the geological conditions of culvert of the South to North Water Transfer Project, lining temperature field of hydraulic tunnel for crack control is simulated by finite element software—ANSYS. According to numerical analysis results of lining temperature field, considering terrain condition, structural characteristics and climate, some engineering measures are taken during construction. Internal temperature of concrete is controlled effectively, concrete crack caused by temperature changes is solved successfully, and construction quality is assured. The difference of measuring data in-situ and calculating data is very small, which illustrate that calculated model is correct and parameters are reasonable. The results can act as reference for the design and construction of similar projects later.

scholarly journals Treatment of Natural Fiber for Application in Concrete Pavement

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Anteneh Geremew ◽  
Pieter De Winne ◽  
Tamene Adugna Demissie ◽  
Hans De Backer
Keyword(s):  
Natural Fiber ◽  
Low Cost ◽  
Natural Fibers ◽  
Specific Treatment ◽  
Fiber Surface ◽  
Drying Shrinkage ◽  
Concrete Technology ◽  
Treatment Techniques ◽  
Concrete Crack ◽  
Concrete Production

Concrete crack is one of the main problems observed in concrete technology due to drying shrinkage. Incorporating fibers in concrete production is one of the mechanisms implemented to mitigate cracks. Nowadays, investigators concentrate on different techniques to replace human-made fiber with existing natural fibers for fiber-reinforced composite material. Utilization of natural fiber has an initiation for the development of eco-friendly materials by reducing damages caused by human-made materials and saving nonrenewable resources. Natural fibers are readily and abundantly available, sustainable, and biodegradable, with low cost and low density, and have superior specific properties. Nevertheless, there are some limitations of natural fiber compared to human-made fiber. Consequently, significant energy was applied to alter natural fiber’s surface and morphology using physical, chemical, and biological treatment techniques to overcome the limitation. The primary intention of surface treatment is to modify the bond between the fiber surface and the polymer matrix. However, based on this literature review, there were no specific treatment techniques to be followed to select the best one from the others as criteria. It should include all parameters to consider starting from the stage from the cradle to the grave, cost of chemicals, transportation, and labors, including energy consumption and effluent energy. Additionally, their environmental effect also investigated in detail to compare each other.

Concrete Crack Control Technology in Chongqing Inch Container Terminal Box Letter of Application in Engineering

2012 ◽  
Vol 217-219 ◽  
pp. 161-164
Author(s):  
Ya Nan Fu ◽  
Ze Ping He
Keyword(s):  
Container Terminal ◽  
Steel Corrosion ◽  
Surrounding Rock ◽  
Rock Deformation ◽  
Control Technology ◽  
Crack Control ◽  
Concrete Crack ◽  
Box Culverts ◽  
And Control ◽  
Surrounding Rock Deformation

This paper mainly introduces the main causes of the concrete cracks, and with Chongqing inch beach bonded port freight container terminal, drain tank letter concrete crack control as the engineering example, the paper analyzes the method of crack control. For example reduce water consumption, choose the narrow fly ash cement, reduce the narrow concrete constraint, and control the hydration heat, strengthen the concrete curing, control the steel corrosion of crack, control the box by letter of the surrounding rock deformation, they can be reached that box culverts basic don't crack effect.

Admixtures in Concrete Crack Control and Construction Technology Optimization

2010 ◽  
Vol 163-167 ◽  
pp. 1115-1120
Author(s):  
Ran Gang Yu ◽  
Xin Hu Wang
Keyword(s):  
Cooling Water ◽  
Design Calculation ◽  
Mass Concrete ◽  
Construction Technology ◽  
Element Analysis ◽  
Crack Control ◽  
Whole Process ◽  
Concrete Crack ◽  
Expansive Agent ◽  
Important Means

This paper studies properties of concrete under the action of water-reducing retarder and expansive agent; gives the optimal design calculation method of cooling water pipe in the construction technology: mainly considering pipe’s diameter, distance, cooling water’s flow, temperature, time etc; studies the optimization to the concretes construction method. Midas/Civil, one finite element analysis soft-ware, analyses mass concrete construction of the whole process of the temperature field and stress field in the numerical simulation, considering the admixtures and construction technology. The results show that commonuse of admixtures and reasonable construction technology are the important means of controlling cracks.

Analysis and Prevention of Early Commercial Concrete Crack with Material Properties

2014 ◽  
Vol 540 ◽  
pp. 209-212
Author(s):  
Li Wei Zhang
Keyword(s):  
Early Modern ◽  
Technology Development ◽  
Early Age ◽  
Urgent Problem ◽  
Concrete Cracking ◽  
Crack Control ◽  
Concrete Crack ◽  
Shrinkage Cracks ◽  
Depth Analysis ◽  
Control Service

Concrete in constant access to technology development, intensification of its early shrinkage cracks caused by problems in the early works become an urgent problem. Early modern concrete easily explained reason for cracking of early age cracking depth analysis of the formation mechanism. And on this basis, the proposed early modern concrete cracks crack control philosophy to early shrinkage of concrete cracking on the goods to instruct the control, service and engineering.

Research on early Concrete Crack Control of Shijiazhuang Subway Construction in Winter

2014 ◽  
Vol 580-583 ◽  
pp. 1134-1137
Author(s):  
Xiang Mei Yu ◽  
Li Jun Cao ◽  
Dong Yang Geng
Keyword(s):  
Temperature Stress ◽  
Civil Engineering ◽  
Difficult Problem ◽  
Construction Quality ◽  
Concrete Cracking ◽  
Crack Control ◽  
Concrete Crack ◽  
Subway Construction

The control of concrete cracking is a complicated and difficult problem for civil engineering. It is more difficult to control the cracking of the concrete poured in the winter. Thorough the analysis of the construction of the Shijiazhuang subway in winter, several methods are integrally applied. Frost proof and decreasing the temperature stress of concrete is considered together. The construction quality of the concrete arrive a satisfied level and the cracking of the concrete is successfully handled.

Novel Pile-to-Pilecap Connection Under Lateral Load

2013 ◽  
Vol 479-480 ◽  
pp. 1115-1118
Author(s):  
Jae Ha Lee ◽  
Woo Seok Kim ◽  
Yong Won Seo ◽  
Kyeong Jin Kim
Keyword(s):  
Absorption Capacity ◽  
Lateral Loads ◽  
Integral Abutment ◽  
Integral Abutment Bridges ◽  
Crack Control ◽  
Crack Patterns ◽  
Concrete Crack ◽  
Abutment Bridges ◽  
Tube Type ◽  
And Performance

Pile-to-pilecap connection such as in integral abutment bridges is vulnerable to lateral loads as well as seismic loads. This connection may govern the bridge strength and performance against various lateral loads. However, previous researches have merely focused on the connection between pile and pilecap. Preliminary study has investigated possible crack patterns between concrete pilecap and steel HP pile using finite element analyses. It was found that the crack patterns are sensitive to the boundary conditions specified in the simulation. The reinforcement detail specified in PennDOT DM4 was barely effective in controlling crack growing but spiral rebar was proved to be effective in delaying crack growth as well as absorbing energy capacity. In this study, two types of connection details of (1) HSS tube type and (2) removed flange type were investigated in terms of crack control. The connection with a HSS tube exhibited to be effective in prevention of crack propagations from the surface of the bottom pilecap. However, second crack was initiated from the corner region of the tube after first crack was arrested; resulting in lower energy absorption capacity compared to both spiral and removed flange details. In the connection with removed flange, concrete crack initiations were mitigated or delayed successfully.

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