Safety and Durability Pavement in Super Long Tunnel

2012 ◽  
Vol 256-259 ◽  
pp. 1411-1414
Author(s):  
Jian Wei Liu ◽  
Jun Min Shen ◽  
Shao Wen Liu

In order to solve the problem of design and construction of pavement structure in the long tunnel, through the analysis of pavement using domestic and overseas, combined with the factors of primary carrying capacity, small temperature gradient in the long tunnel, the Continuously Reinforced Concrete Pavement(CRCP) is proposed, which has characteristics of better durability, strong structure integrity and comfortable driving. Mini excavator auxiliary framing construction, layered pouring concrete, lap joint construction of welded steel have solved a series of problems of the relatively small space of construction, the lower concrete vibrators affected by the steel mesh and reinforced scene lashing. So continuously reinforced concrete pavement using welded steel fabric can be used as a major road structure in long tunnel.

Author(s):  
Yoon-Ho Cho ◽  
Terry Dossey ◽  
B. Frank Mccullough

The effect of coarse aggregate on pavement performance has been attributed to the volume of aggregate used in pavement construction. The different patterns of crack development for limestone (LS) and siliceous river gravel (SRG) are a typical example of aggregate-induced variable performance in continuously reinforced concrete pavement (CRCP). An attempt was made to find a reasonable solution for pavements with SRG. As a way to solve the performance problem observed from the SRG pavement, a blended aggregates mixture was suggested. Laboratory and field tests were performed to check the feasibility of their application in pavements. From the laboratory test, a 50:50 blending ratio was suggested after considering the effect on tensile strength and thermal coefficient of expansion. Field test sections were also constructed to verify previous performance observations for the two aggregates and to provide performance data for new variables such as blended aggregates and special curing methods. Unexpectedly, the blended mixture did not improve the performance of SRG pavement; rather it experienced worse cracking than SRG alone. A controlled experiment with additional field test sections is needed to verify or disprove this finding. The only definitive finding was that selection of aggregate in the concrete pavement is a vital consideration for the design of the pavement. The CRCP8 analytical program reasonably predicted crack spacing for both SRG and LS pavements, predicting mean crack spacing of 0.99 m (3.25 ft) for SRG and 1.98 m (6.41 ft) for the limestone. These values are somewhat below the actual spacing observed at 100 days. Data collected after the first winter period will be required to calibrate the program.


2016 ◽  
Vol 3 ◽  
pp. 52-55 ◽  
Author(s):  
Rainer Pauska ◽  
Umut Cakmak ◽  
Rainer Lottes ◽  
Zoltan Major

Joining experiments using different adhesives were carried out. In addition to the adhesive, the specimens were also treated with ultrasonic waves to improve the load carrying capacity of the joined parts. Lap joint shear tests have been conducted to quantify this improvement.


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