Field Application of High-Strength Deep Mixing Method for Waste Water Pipeline in Soft Ground

Author(s):  
E. C. Shin ◽  
J. K. Kang ◽  
Y. K. Rim ◽  
J. J. Park
2020 ◽  
Vol 27 (1) ◽  
pp. 455-463
Author(s):  
Lixia Guo ◽  
Minghua Wang ◽  
Ling Zhong ◽  
Yanan Zhang

AbstractThe internal curing technology has been widely applied to high-strength concrete, for it can make the high-strength concrete marked by low shrinkage and durable frost resistance. The key to its extension and application lies in the reasonable mixing amount of internal curing materials. To address this problem, scholars have proposed a method for determining the water demand in internal curing; however, the water release of internal curing materials is difficult to obtain by measurement due to the mixing method. Therefore, this paper proposed a calculation model for the mixing amount of internal curing materials based on the modified MULTIMOORA method (Multi-Objective Optimization on the basis of Ratio Analysis plus full multiplicative form). First, different internal curing materials (super absorbent polymer (SAP), lightweight aggregate (LWA)) and pretreatment methods were selected to calculate their compressive strength, self-shrinkage and frost durability according to a proposed test scheme on the mixing amount of internal curing materials, and in such case, the comprehensive performance evaluation of the above indexes was turned into a multi-attribute decision-making problem. Second, the ordered weighted averaging (OWA) method and the entropy weight method were used to determine the subjective and objective weights of the indexes respectively, to eliminate the impact of outliers in the subjective evaluation values. Finally, the comprehensive performance of each test group was sorted using MULTIMOORA, and based on the sorting results and the calculation model, the mixing amount of internal curing materials was determined. The numerical example application results showed that the mixing amount of SAP curing material calculated based on the model herein was 1.276 kg/m3, and the mixing method adopted the pre-water absorption method with the total water-binder ratio unchanged. The numerical example evaluation results were in good agreement with the test results. The internal curing effect of SAP was better than that of LWA, and reached the best when the mixing amount was calculated at 25 times the water release rate and the requirement for the maximum total water diversion was met. The study may provide new ideas for extension and application of the internal curing technology.


2021 ◽  
pp. 100233
Author(s):  
Koki Nakao ◽  
Shinya Inazumi ◽  
Toshiaki Takaue ◽  
Shigeaki Tanaka ◽  
Takayuki Shinoi

Grouting 2017 ◽  
2017 ◽  
Author(s):  
Ignazio Paolo Marzano ◽  
Massimo Grisolia ◽  
Giuseppe Iorio ◽  
Giuseppe Panetta ◽  
Raffaele Papa

Author(s):  
Nicholas J. Venero ◽  
Tim J. M. Bond ◽  
Raymond N. Burke ◽  
David J. Miles

A new technology for external rehabilitation of pipelines, known as XHab™, has been developed. This method involves wrapping multiple layers of ultra-high strength steel (UHSS) strip in a helical form continuously over an extended length of pipeline using a dedicated forming and wrapping machine. The reinforcement afforded by the strip can be used to bring a defective section of pipe (e.g. externally corroded or dented) back to its original allowable operating conditions, or even to increase the allowable operating pressure if the desired operating conditions exceed the original pipeline design limits. This paper describes the design, manufacture and testing process for a self-propelled wrapping machine for in-field rehabilitation. The wrapping apparatus consists of several major components including an opening sufficiently wide to receive the pipe, a movement assembly, a winding head, a preforming device, an accumulator and an oscillating adhesive applicator. The wrapping apparatus uses the winding head to wrap the reinforcing steel strip around the pipe. The movement assembly uses a pair of tracks in contact with the pipe to drive the wrapping apparatus along which enables helical wrapping of the reinforcing strip material. The oscillating adhesive assembly applies structural adhesive to the pipe immediately before the strip is wound. The winding head, motive assembly and adhesive applicator are electronically synchronized to one another to enable precise control of pitch and adhesive volume. The paper also describes the field application of XHab including mobilization/demobilization of equipment and interaction with other rehabilitation equipment, as well as specific aspects such as initiation and termination of wrapping, protection of rehabilitated area and implementation of cathodic protection.


2016 ◽  
Vol 56 (3) ◽  
pp. 559-573 ◽  
Author(s):  
Kiyoshi Yamashita ◽  
Junji Hamada ◽  
Tomohiro Tanikawa

Author(s):  
Abheetha Peiris ◽  
Issam Elias Harik

In the past, a number of steel girder-reinforced concrete deck bridges on county roads in the United States have been built as non-composite. Most of these bridges currently have load postings limiting the capacity of bus and truck loads on their roadways. Recent research showed that post installed high strength bolts could be used as shear connectors in rehabilitation work to achieve partial composite design by deploying 30% to 50% of the connectors typically required for a full composite design. This paper presents details on the analysis, design, and field application of post-installed shear connectors on a non-composite concrete deck steel girder bridge in Kentucky. In order to minimize traffic disruption and construction costs, the shear connectors were inserted on the bottom side of the deck through the top flange of the steel girder. While the load rating increased by 132%, field tests conducted before and after installation of the shear connectors showed that the bridge's live load deflections were reduced by more than 27%.


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