A new method for formulating crack spacing models of RC ties

Cracking of concrete is one of the most complicated phenomena in reinforced concrete analysis and is one of the key aspects governing serviceability analysis of RC structures. Current methods for investigating cracking rely on empirical approaches that give unreliable results with errors of multiple times the real value. A new non-empirical method based on the combination of the stress-transfer and the smeared approaches is proposed for deriving crack spacing models. The stress-transfer approach governs the strain distribution of the reinforcement between the consecutive cracks whereas the smeared approach allows for the estimation of the mean strain of the element. The suggested method introduces the concept of damage zones: the bond in the area adjacent to the normal cracks is considered to be fully damaged, thus bond behaviour is non-uniform in the segment between cracks. Crack spacing models were derived using the load-strain analysis method presented in the Eurocode 2 and were shown to give results that are in good agreement with the crack spacing values taken from available experimental data

Deformation analysis of fibre-reinforced polymer reinforced concrete beams by tension-stiffening approach

Fibre-reinforced polymer (FRP) is free from corrosion problem and is a viable alternative reinforcement material for concrete structures in lieu of steel reinforcing bars. Since FRP has lower elastic modulus compared to steel, the serviceability aspect of FRP reinforced concrete (FRP-RC) members should be particularly considered in the structural analysis and design. This study addresses the deformation analysis of FRP-RC flexural members with thorough consideration of the tension-stiffening phenomenon in post-cracking state. The approaches for analyzing the tension-stiffening flexural response of FRP-RC beams are presented. These include the use of empirical or theoretical models to compute effective flexural stiffness, the use of finite element method in conjunction with nonlinear constitutive material models, and the use of tensile stress block in combination with member analysis. Among them, the latter is a relatively simple analysis approach. Aiming for serviceability assessment of FRP-RC beams in structural engineering practice to circumvent sophisticated theoretical approaches and constitutive models, parametrized tensile stress block is derived based on tension stress fields computed from finite element analysis, and is proposed for use in member analysis for prediction of deflections. Four FRP-RC beam specimens tested in the literature are analyzed to verify the proposed tensile stress block. Close agreement between the experimental and analytical results is achieved, thereby endorsing the applicability and reliability of the proposed method.European Social Fund (Project No. 09.3.3-LMT-K-712-01-0145) under a grant agreement with the Research Council of Lithuania (LMTLT)

Discussion: Tension stiffening in concrete beams. Part I: Fe analysis

published_or_final_versio

Integration of decision support systems to improve decision support performance

Decision support system (DSS) is a well-established research and development area. Traditional isolated, stand-alone DSS has been recently facing new challenges. In order to improve the performance of DSS to meet the challenges, research has been actively carried out to develop integrated decision support systems (IDSS). This paper reviews the current research efforts with regard to the development of IDSS. The focus of the paper is on the integration aspect for IDSS through multiple perspectives, and the technologies that support this integration. More than 100 papers and software systems are discussed. Current research efforts and the development status of IDSS are explained, compared and classified. In addition, future trends and challenges in integration are outlined. The paper concludes that by addressing integration, better support will be provided to decision makers, with the expectation of both better decisions and improved decision making processes

Factors Influencing Post-disaster Reconstruction Project Management for Housing Provision in the Gaza Strip, Occupied Palestinian Territories

In the Occupied Palestinian Territories, the Gaza Strip has suffered regular cycles of reconstruction due to systematic destruction during Israeli military operations, as in 2006, 2008–2009, 2012, and 2014. In this context of ongoing conflict this article aims to identify, rank, and discuss the most important factors influencing post-disaster reconstruction project management (PDRPM) for housing in the Gaza Strip. A set of key factors that influence PDRPM were assembled as a result of a global literature review. A questionnaire survey was conducted, and the obtained data were analyzed using a relative importance index for each PDRPM factor. Findings are presented in six groups: housing approaches, organizational behavior, project funding, supply chain and logistics, communication and coordination, and PDRPM context. Findings indicate that the most significant factors that influence PDRPM for housing provision in the Gaza Strip are related to issues associated with financial resources. It is critical that sufficient funding should be available in order to allow organizations to undertake housing projects in an effective and efficient way. Joint efforts are required from international donors and local organizations in order to effectively manage financial resources with the ultimate goal of improving PDRPM for housing provision

A non-linear third-order triangular laminated plate element for analysis of cracked rc slabs and beams/Trečios eilės trikampio sluoksniuoto elemento panaudojimas supleišėjusių gelžbetoninių plokščių ir sijų analizei

Straipsnyje pateiktas universalus sluoksniuotos plokštės netiesinės medžiagos baigtinių elementų modelis, pritaikytas supleišėjusios gelžbetoninės plokštės skaičiavimui. Pasirinktas sudėtingas analitiškai suformuotas trečios eilės trikampis sluoksniuotas Reisnerio-Mindlino plokštės elementas, turintis 50 laisvės laipsnių. Programa įvertina atskirų plokštės sluoksnių netiesines deformacijas, supleišėjimą. Betono fizikiniame modelyje įvertinta tempiamo ir gniuždomo betono įtempimų-deformacijų diagramos žemyn krentanti dalis. Skaičiavimo modelis ir programa patikrinti, atlikus turimų ir teorinių rezultatų palyginimą. Straipsnyje pateiktų gelžbetoninės sijos ir plokštės paskaičiuoti įlinkiai gerai atitiko eksperimentinius. First Published Online: 26 Jul 201