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A platform for research: civil engineering, architecture and urbanism
Strength models for uPVC-confined concrete
Highlights Four-terminal-architecture CEDTS is proposed for thermal error control. Hyper-parameters of ILSTM network are optimized by ISOA. Comprehensive machining error model is constructed according to HCT theory. Data services, including clustering analysis, status monitoring, and data funsion, are provided. GPU-based cloud computing layer is used to expedite executing process.
Abstract In the present study, an experimental program was executed to investigate the performance of a composite structural system under direct compression load. The system consists of a uPVC tube as the mold for pouring the fresh concrete and a confining device for structural concrete. Three thicknesses of plastic tubes (4, 5, 7 mm) were investigated using four sets of three stub columns. Rice husk ash (RHA) was used as a cement replacement material to improve the strength and other mechanical properties of concrete core with target compressive strengths of 30 MPa for sets one and two and 60 MPa for sets three and four, respectively. The load capacity of uPVC strengthened blended concrete improved, and the ultimate failure is ductile due to the elongation capacity of the polymeric tube. To examine the post-peak behavior of the confining device at near-collapse conditions, two stub columns were subjected to five repeated loading that almost produced full collapse conditions in each cycle of loading after the first cycle. The tubes effectively dissipated energy by plastic yielding, which could be considered a partial progressive failure. Several analytical expressions have been proposed, in total twenty-four, for predicting the strength capacity of the composite system. However, most of these empirical expressions have been derived based on limited experimental tests. Therefore, to assess the performance of the existing strength models in predicting the capacity of PVC-confined concrete (PCC) and uPVC-confined concrete (uPCC); a comprehensive database of 389 test results was assembled from the published literature that covers the studies published in the period 1979–2021 combined with the twelve data from the present study. To account for the height/diameter ratio (H/D), three cases were examined; case one (3 ≤ H/D >3), case two (H/D ≤ 3), and case three (H/D >3). Based on the compiled database, two strength-based confinement models were proposed for circular concrete specimens confined externally with PVC or uPVC tube. The two models include several parameters that influence the properties of the concrete core and the confining device. The proposed models are the most accurate among all the models yielding lower values of absolute average error for the three cases examined.
Strength models for uPVC-confined concrete
Highlights Four-terminal-architecture CEDTS is proposed for thermal error control. Hyper-parameters of ILSTM network are optimized by ISOA. Comprehensive machining error model is constructed according to HCT theory. Data services, including clustering analysis, status monitoring, and data funsion, are provided. GPU-based cloud computing layer is used to expedite executing process.
Abstract In the present study, an experimental program was executed to investigate the performance of a composite structural system under direct compression load. The system consists of a uPVC tube as the mold for pouring the fresh concrete and a confining device for structural concrete. Three thicknesses of plastic tubes (4, 5, 7 mm) were investigated using four sets of three stub columns. Rice husk ash (RHA) was used as a cement replacement material to improve the strength and other mechanical properties of concrete core with target compressive strengths of 30 MPa for sets one and two and 60 MPa for sets three and four, respectively. The load capacity of uPVC strengthened blended concrete improved, and the ultimate failure is ductile due to the elongation capacity of the polymeric tube. To examine the post-peak behavior of the confining device at near-collapse conditions, two stub columns were subjected to five repeated loading that almost produced full collapse conditions in each cycle of loading after the first cycle. The tubes effectively dissipated energy by plastic yielding, which could be considered a partial progressive failure. Several analytical expressions have been proposed, in total twenty-four, for predicting the strength capacity of the composite system. However, most of these empirical expressions have been derived based on limited experimental tests. Therefore, to assess the performance of the existing strength models in predicting the capacity of PVC-confined concrete (PCC) and uPVC-confined concrete (uPCC); a comprehensive database of 389 test results was assembled from the published literature that covers the studies published in the period 1979–2021 combined with the twelve data from the present study. To account for the height/diameter ratio (H/D), three cases were examined; case one (3 ≤ H/D >3), case two (H/D ≤ 3), and case three (H/D >3). Based on the compiled database, two strength-based confinement models were proposed for circular concrete specimens confined externally with PVC or uPVC tube. The two models include several parameters that influence the properties of the concrete core and the confining device. The proposed models are the most accurate among all the models yielding lower values of absolute average error for the three cases examined.
Strength models for uPVC-confined concrete
Abduljabar Abdulla, Nwzad (author)
2021-09-26
Article (Journal)
Electronic Resource
English
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