Ruentex Group

Taipei, Taiwan

Ruentex Group

Taipei, Taiwan
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Shih T.-H.,National Chiao Tung University | Chen C.-C.,National Chiao Tung University | Weng C.-C.,National Chiao Tung University | Yin S.Y.-L.,Ruentex Group | Wang J.-C.,Ruentex Group
Journal of Constructional Steel Research | Year: 2013

The axial compressive capacity and load-displacement behaviour of composite columns confined by two interlocking spirals were experimentally and analytically investigated. The innovative spiral cage used for a square column was fabricated by interlocking a circular spiral and a star-shaped spiral to enhance the confinement effect for the core concrete. Eight full-scale square composite columns were tested under monotonically increased axial compression. Experimental results demonstrated that, with significant savings of the transverse reinforcement, the composite columns confined by two interlocking spirals achieved excellent axial compressive strength and ductility capacity. Moreover, an analytical model was developed to take into account the concrete confinement due to the structural steel in addition to the transverse reinforcement and distributions of the longitudinal bars. The analytical results accurately predicted the axial compressive capacity and load-displacement behaviour of the specimens. Consequently, the application of the two interlocking spirals in a square composite column appears to be very affirmative. © 2013 Elsevier Ltd.


Liang C.-Y.,National Chiao Tung University | Chen C.-C.,National Chiao Tung University | Weng C.-C.,National Chiao Tung University | Yin S.Y.-L.,Ruentex Group | Wang J.-C.,Ruentex Group
Journal of Constructional Steel Research | Year: 2014

This study elucidates experimentally and analytically the axial compressive load-carrying capacity and behavior of square composite steel and concrete columns confined by multiple interlocking spirals. The variables of the specimens included type of the lateral reinforcement (rectilinear hoops and multiple spirals), spacing of the lateral reinforcement, and shape of the structural steel section (cruciform and box-shaped). Specimens were tested under monotonically increased axial load. The test results demonstrated that the composite columns with multiple spirals achieved great axial load-carrying capacity and deformability because of the excellent concrete confinement attributed to the multiple interlocking spirals and the structural steel section. Smaller spacing of the spirals and larger area of the highly confined concrete in the composite columns resulted in the better strength and ductility of the columns. An analytical model was proposed to calculate the load-displacement relations of the specimens, and the model predicted well the behavior of the specimens. The effectiveness of the multiple interlocking spirals in the square composite columns was evident via this study. © 2014 Elsevier Ltd.


Chen Y.,Nanjing Southeast University | Feng J.,Nanjing Southeast University | Yin S.,Ruentex Group
Computers and Concrete | Year: 2012

Numerical studies are performed to predict the stress-strain behavior of rectangular RC columns confined by multi-spiral hoops under axial and eccentric compressions. Using the commercial finite element package ABAQUS, the Drucker-Prager criterion and the yield surface are adopted for damaged plasticity concrete. The proposed finite element models are compared with the published experimental data. Parametric studies on concrete grades, confinement arrangement, diameter and spacing of hoops and eccentricity of load are followed. Numerical results have shown good agreements with experimental values, and indicated a proper constitutive law and model for concrete. Cross-sectional areas and spacing of the hoops have significant effect on the bearing capacity. It can be concluded that rectangular RC columns confined by multi-spiral hoops show better performance than the conventional ones.


Ping Tserng H.,National Taiwan University | Yin S.Y.-L.,National Taiwan University | Yin S.Y.-L.,Ruentex Group | Lee M.-H.,National Taiwan University
Journal of Civil Engineering and Management | Year: 2010

The construction industry consists of many unstructured documents, which accumulate a large volume of tacit knowledge. In the general domain, a Knowledge Map can illustrate connections of knowledge and transfer tacit knowledge to explicit knowledge, but this is unsuitable on specific domain such as construction industry. This research generalized existing mapping rules to be applied to general and specific domain; and presented a novel and practical model for building knowledge map, named Knowledge Map Model (KMM). This model comprised of five procedures, including identifying problems, discussing with experts and users, establishing the classification structure, establishing the document base, and deciding the display model. Furthermore, this research establishes Knowledge Map Model System (KMMS) as a major tool to improve the knowledge map reused and shared among the practical process. Finally, this research validated the KMM in a real project of bridge maintenance.


Tserng H.P.,National Taiwan University | Yin S.Y.-L.,National Taiwan University | Yin S.Y.-L.,Ruentex Group | Ngo T.L.,National Taiwan University | Ngo T.L.,National University of Civil Engineering
Journal of Marine Science and Technology (Taiwan) | Year: 2013

Prebid planning is an essential function of construction project management that allows contractors to obtain projects with low cost while achieving other criteria. It also helps contractors during project execution and management. This research applied the manufacturing industry's lean theory to propose a lean prebid planning model (LPPM) for construction contractors. The LPPM can significantly eliminate the main types of waste in construction projects because it effectively combines three important concepts inthe manufactureing industry: transformation, workflow, and value generation. This modelincludes seven arrangement steps, which are described systematically to help contractors with real-world applications. A case study was implemented to demonstrate the accuracy and usefulness of the proposed model. The results showed a reduction of 9.1% in project cost and 37 days in project duration.


Huang W.-H.,National Taiwan University | Huang W.-H.,Long Reign Development Co. | Tserng H.P.,National Taiwan University | Liao H.-H.,National Taiwan University | And 4 more authors.
Automation in Construction | Year: 2013

Although construction contractor prequalification highly prioritizes the financial capacity of the construction contractors, a special assessment of contractors' financial capacities has seldom been performed in the construction industry. Cash flows largely reflect a contractor's capacity to meet its financial obligations, this study assesses the credit qualities of construction contractors by using a cash flow based credit model (CFB credit model). The model uses historical continuously free cash flow to firm of construction contractors to simulate possible future cash flow paths. The credit quality scores of construction contractors are then assessed using the CFB credit model. The results demonstrate the effectiveness of assessment of the credit quality of construction contractors, and recommend the clients to adopt it in prequalification of the contractors' financial abilities. © 2013 Elsevier B.V.


Yin S.Y.-L.,National Taiwan University | Yin S.Y.-L.,Ruentex Group | Tserng H.P.,National Taiwan University | Toong S.N.,Ruentex Group | And 2 more authors.
Journal of Civil Engineering and Management | Year: 2014

The subcontracting procurement process is one of the most important issues impacting the costs of engineering projects and construction projects, in particular. Traditional procedures of subcontracting procurement tend to limit the opportunities for price negotiation and cooperative relationships between contractors and neglect potential issues such as engineering interface, construction risk, and waste. Based on case studies of construction projects, we propose a "lean" subcontracting procurement process (LSPP) drawing from lean construction theory. The process consists of a novel Seven-Arrangement operation plan and four types of standard operating flows. Not only does the proposed LSPP help sub-contractors eliminate various types of waste in construction projects, it also establishes a common information platform and cooperative environment that help participating contractors understand the work emphasis of each operation and the whole operation in sequence. As a result, the relationships between participating contractors become cooperative, potential risks in construction projects can be discovered early, and profits are shared between contractors. Thus, this process allows contractors to obtain long-term benefits. © 2014 Copyright © 2014 Vilnius Gediminas Technical University (VGTU) Press.


Wu T.-L.,Engineering and Construction Co. | Ou Y.-C.,National Taiwan University of Science and Technology | Yen-Liang Yin S.,Ruentex Group | Wang J.-C.,Engineering and Construction Co. | And 2 more authors.
Journal of the Chinese Institute of Engineers, Transactions of the Chinese Institute of Engineers,Series A/Chung-kuo Kung Ch'eng Hsuch K'an | Year: 2013

This study investigates the behavior of transversely reinforced oblong and rectangular bridge columns under combined axial and flexural loading, including eccentric compression and lateral cyclic loading under constant axial load. The transverse reinforcement schemes include conventional tie and multi-spiral reinforcement. The multi-spiral reinforcement for the oblong column comprises two interlocking spirals and, for rectangular columns, comprises two interlocking large central spirals interlocked with four small spirals at the corners. The amount of transverse reinforcement for all of the columns conforms to the current seismic bridge design specifications. Test results indicate that all of the columns exhibit ductile behavior with ductility capacities significantly higher than the ductility capacity required by the design code. The oblong spiral column with an amount of transverse reinforcement 43% that of the corresponding tied column shows strength, ductility, energy dissipation, and over-strength similar to the tied column. Additionally, the rectangular spiral column with an amount of transverse reinforcement 59% that of the corresponding tied column exhibits strength, ductility, energy dissipation and over-strength superior to the tied column. Moreover, the code P-M interaction analysis method can provide a conservative means of estimating nominal moment strength. The two code methods to determine the maximum probable moment strengths may not provide conservative estimates. Results of this study demonstrate that the maximum probable moment of the columns examined can be estimated conservatively as 1.4 times the nominal moment strength. © 2013 The Chinese Institute of Engineers.


Ou Y.-C.,National Taiwan University of Science and Technology | Ou Y.-C.,State University of New York at Buffalo | Ngo S.-H.,National Taiwan University of Science and Technology | Ngo S.-H.,Hong Duc University | And 5 more authors.
ACI Structural Journal | Year: 2014

An innovative seven-spiral transverse reinforcement is proposed for oblong reinforced concrete bridge columns. Compared to conventional single-spiral or two-spiral transverse reinforcement, the proposed scheme reduces the size of the spirals and hence improves the constructibility of spirals for large bridge columns. Four seven-spiral columns were tested under high shear stress to assess their performance. Comparable conventional tied and two-spiral columns were also tested. Test results showed that spirals in the proposed seven-spiral columns remained interlocked. With less transverse reinforcement, the seven-spiral columns achieved similar or better shear performance compared to the tied columns. The seven-spiral column exhibited the highest effective shear coefficient, followed by the two-spiral column and the tied column. Comparison of shear-strength predictions with the test results shows that the ACI 318 model generally provides conservative estimates, and the Caltrans SDC and Sezen models provide reasonable estimates of experimental behavior in terms of failure point prediction. © 2014, American Concrete Institute.


Yin Y.-L.,Ruentex Group | Cheng R.-B.,uentex Materials Co. | Chiang S.-C.,uentex Materials Co.
Journal of the Chinese Institute of Civil and Hydraulic Engineering | Year: 2014

The rheological property of Portland cement affects the workability of fresh concrete. The cement chemical component is one of crucial effects on change rheological property of cement paste, especially on the fresh concrete made with polynaphthalene sulfonate superplasticizer (PNS). In this study, over 60 sampling Portland type I cement, and the cement paste made by w/c=0.3 were used to investigate on the cement chemical components/type of superplasticizers with slump loss of cement paste. Test result shows that the cement paste made with Polycarboxylate superplasticizer have higher fluidity during the first minutes and lower fluidity loss in 90 minutes than the cement paste made with polynaphthalene sulfonate superplasticizer. It indicates that the polynaphthalene sulfonate superplasticizer used in cement paste is lower compatibility, and the cement paste rheological property is high affected by cement chemical component. The fluidity loss increases with the increasing the content of sodium oxide, Potassium oxide, and sulfate oxide of cement. The optimum content of sodium oxide, Potassium oxide, and sulfate oxide for the fluidity loss within 20% in 90 minutes should be controlled lower than 0.333%, 0.784%, and 2.23%, respectively. ©, 2014, Chinese Institute of Civil and Hydraulic Engineering. All right reserved.

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