The Construction Technique of Steel-Wood Composite Core Formwork in a Large Span Prestressed Hollow Box Guider

2014 ◽  
Vol 894 ◽  
pp. 18-21
Author(s):  
Jing Liang Yu
Keyword(s):  
Low Cost ◽  
Wood Composite ◽  
Construction Technique ◽  
Box Girder ◽  
Counter Measures ◽  
Large Span ◽  
Working Efficiency

Based on the comparison of several types of core formwork for large span hollow box girder, their structural characters, and assemble and disassemble in application is analysed to find that steel-wood core formwork is a better choice. Then the installation technique of steel-wood core formwork is discussed, including assemble, disassemble and anti-floating counter measures. The practice in some large span prestressed hollow box girder construction prove that steel-wood core formwork is a simple but effective core formwork construction technique with technological economic advantages because of its low cost, high working efficiency and better accuracy..

Repair of Major Cracks in Central Spans of the 4 Span Continuous Bridge, India

2018 ◽  
Author(s):  
Dhananjay A. Bhide ◽  
Prashant Dongre
Keyword(s):  
Construction Material ◽  
Remedial Measures ◽  
Construction Technique ◽  
Box Girder ◽  
Material Parameters ◽  
National Highway ◽  
Major Crack

Varsova Bridge is across Vasai Creek, about 35 Km from Mumbai, India. It is on National Highway 48. Two bridges, 555.32m long, exist at the crossing, built in 1970 and 2004 respectively. Old bridge has central 4 spans, built in continuous PSC box girder su configuration of 57.3 + 2 x 114.6 + 57.3 construction technique. 114.6m span on Mumbai end developed a major crack, 4mm wi about 12m from mid span. Main c height in both webs. The paper describes the investigations made through analysis the probable reasons and deciding remedial measures as well as execution of the same. used four different models as per construction material parameters. Final repair measure crack locations.

scholarly journals Study on force of steel bracket for construction of large span and wide steel box girder

2019 ◽  
Vol 490 ◽  
pp. 032013
Author(s):  
Deyuan Deng ◽  
Xiaoqing Zhang ◽  
Zhou Chen ◽  
Guofei Yang ◽  
Jianxin Lu
Keyword(s):  
Box Girder ◽  
Large Span ◽  
Steel Box Girder

Study on Early Cracking Resistance of PC Box Girder Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 1786-1792
Author(s):  
Wei Chun Zhong ◽  
Xiao Yi Zhang ◽  
Hui Zhou ◽  
Chuang Sheng Zheng
Keyword(s):  
Hydration Heat ◽  
Maximum Temperature ◽  
Strength Development ◽  
Cracking Resistance ◽  
Construction Stage ◽  
Maximum Temperature Difference ◽  
Construction Technique ◽  
Box Girder ◽  
Mixture Ratio ◽  
Girder Bridges

Early cracks of box girder are widespread during the construction stage of PC box girder bridges. The cracking resistance of a prestressed concrete continuous beam bridge was conducted from the point of construction technique. Experimental study on hydration heat and mechanical properties of box girder concrete at early age were carried out. The results shown that the casting temperature of the concrete, the peak temperature and the maximum temperature difference between inside and outside of the hydration heat were very low, which were 15.7°C, 8°C and 10.2°C, respectively. The strength development of the concrete was stable, and the mixture ratio was optimal. The concrete appearance quality was fairly good without visible cracks in the construction stage. The study reveals that the crack of girder bridges during the construction stage can be avoided by taking effective measures in the construction.

scholarly journals A New Cable-Less Seismograph with Functions of Real-Time Data Transmitting and High-Precision Differential Self-Positioning

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 4015
Author(s):  
Kang Liu ◽  
Qingyu You ◽  
Juan Wang ◽  
Xiqiang Xu ◽  
Pengcheng Shi ◽  
...  
Keyword(s):  
Real Time ◽  
High Precision ◽  
Low Cost ◽  
Area Network ◽  
Time Data ◽  
Zigbee Technology ◽  
Field Quality ◽  
Potential Applications ◽  
Differential Positioning ◽  
Working Efficiency

This study developed a new cable-less seismograph system, which can transmit seismic data in real-time and automatically perform high-precision differential self-positioning. Combining the ZigBee technology with the high-precision differential positioning module, this new seismograph system utilized the wireless personal area network (WPAN) and real-time kinematic (RTK) technologies to improve its on-site performances and to make the field quality control (QC) and self-positioning possible. With the advantages of low-cost, good scalability, and good compatibility, the proposed new cable-less seismograph system can improve the field working efficiency and data processing capability. It has potential applications in noise seismology and mobile seismic monitoring.

scholarly journals An effective technique for constructing wood composite with superior dimensional stability

Holzforschung ◽  
2020 ◽  
Vol 74 (5) ◽  
pp. 435-443
Author(s):  
Xiaoshuai Han ◽  
Zhenxing Wang ◽  
Qinqin Zhang ◽  
Junwen Pu
Keyword(s):  
Mechanical Properties ◽  
Dimensional Stability ◽  
High Performance ◽  
Low Cost ◽  
Sem Analysis ◽  
Wood Composite ◽  
Engineering Structures ◽  
Natural Wood ◽  
Dimensional Instability

AbstractFast-growing wood is an abundant and low-cost material and is widely used for structural building and furniture construction. However, inferior mechanical properties and dimensional instability limit its application in advanced engineering structures. Herein, we developed a simple, effective and “green” method to transform bulk poplar into a high-performance wood composite. The wood composite was prepared by the impregnation of the itaconic acid (IA) solution acting as a grafting anchor into the wood matrix, followed by in situ polymerization of styrene upon heating to form a hydrophobic polymer within the wood scaffold. Scanning electron microscope (SEM) analysis revealed that hydrophobic polystyrene (PS) was deposited in wood cell walls and lumens, leading to a reduced water uptake and remarkably enhanced dimensional stability, as well as generally improved mechanical properties. In addition, the PS generated improvement in the thermal stability of the wood composite in comparison with that of natural wood (W).

The Construction Technique of the Beam Slab Structure being Filled Large-Span Prestressed Lightweight Materials

2013 ◽  
Vol 743 ◽  
pp. 73-77
Author(s):  
Jun Li Yuan
Keyword(s):  
Prestressed Concrete ◽  
New Technology ◽  
Rapid Development ◽  
Technical Problem ◽  
Chinese Economy ◽  
Large Space ◽  
Construction Technique ◽  
Technical Problems ◽  
Large Span ◽  
Light Material

Abstract: With the rapid development of Chinese economy, more and more requirements of large public buildings, large space and has more functions, the engineering design, construction and bring many technical problems, in order to solve the technical problem, the construction of scientific research departments continue to research and development of new materials, new technology, new methods of construction, city of Puyang stadium the tennis project 44M*24M large span structure, adopts the ‘made of light material combined unit filled prestressed concrete cast-in-situ slab’ structure technology, solves the light, save steel, concrete, reduces the structure thickness, good economic practicability.

scholarly journals Simply-supported Box Girder Construction Technique of 40 m Movable Formwork Method Cast-in-Situ Railway Passenger Dedicated Line

2015 ◽  
Vol 4 (4) ◽  
pp. 30
Author(s):  
Zhemin Li
Keyword(s):  
Bearing Capacity ◽  
Cost Reduction ◽  
Time Limit ◽  
Type Number ◽  
Construction Technique ◽  
Box Girder ◽  
Simply Supported ◽  
Railway Passenger ◽  
Passenger Dedicated Line

<p>The movable formwork has the characteristics of light self weight, large bearing capacity, small rod type number, rapid assembling, and simplicity to construct. Therefore, when cast-in-situ concrete box girder is constructed, the moveable formwork has great meanings in cost reduction and project time limit shortening. By using this method, the difficulty that brackets cannot be distributed as the ground bearing capacity of bridges. Besides that, bridge sites is low is reasonably solved, cost of material and labor can be reduced, influence to underbridge is minimize, and the construction progress is accelerated. The simply-supported box girder construction technique of 40 m movable formwork method cast-in-situ railway passenger dedicated line is particularly analyzed.<strong></strong></p>

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