{"title":"Sagging behavior of precast NC beams with HPCs-filled wet joints incorporating pre-stressing technique","authors":"Ahmed Hamoda , Galal Elsamak , Basant ramadan","doi":"10.1016/j.cscm.2025.e04997","DOIUrl":null,"url":null,"abstract":"<div><div>Precast segmental beams constructed with normal concrete (NC) are widely adopted in modern infrastructure because of their advantages in decreasing on-site labor, shortening construction time, and observing high-quality control. Such segmental beams might require using construction joint with superior characteristics. However, the presence of intermediate constriction joints introduces potential weaknesses, particularly under sagging loading, which may result in bond degradation, cracking, or interface failure. This investigation presents a comprehensive experimental and numerical investigation into the flexural performance of precast NC beams incorporating high-performance concrete (HPC)-filled wet joints of varying developed lengths (l<sub>d</sub>), subjected to post-tensioning force. A total number of nine full-scale beams were experimented under flexural moments until failure. The considered parameters were: HPC type employed in the joint (ultra-high performance concrete (UHPC) and engineered cementitious composite (ECC)), the l<sub>d</sub> values (15, 20, and 25 times the bar diameter (D)), and the pressurising condition applied through of post-tensioning system. The results demonstrated that specific combinations of these parameters significantly enhanced cracking resistance, initial stiffness and energy absorption. Moreover, integrating a pre-stressing system with a UHPC-filled wet joint and a developed length of 25D led to an approximate 98 % increase in ultimate load. A nonlinear three-dimensional finite element model (FEM) was constructed and validated against the experimental outcomes, yielding high accuracy with discrepancies less than 4 %. Additionally, a novel predictive equation for the ultimate moment capacity of the studied beams was formulated, exhibiting a mean error margin of about 3 %.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04997"},"PeriodicalIF":6.6000,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Case Studies in Construction Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2214509525007958","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Precast segmental beams constructed with normal concrete (NC) are widely adopted in modern infrastructure because of their advantages in decreasing on-site labor, shortening construction time, and observing high-quality control. Such segmental beams might require using construction joint with superior characteristics. However, the presence of intermediate constriction joints introduces potential weaknesses, particularly under sagging loading, which may result in bond degradation, cracking, or interface failure. This investigation presents a comprehensive experimental and numerical investigation into the flexural performance of precast NC beams incorporating high-performance concrete (HPC)-filled wet joints of varying developed lengths (ld), subjected to post-tensioning force. A total number of nine full-scale beams were experimented under flexural moments until failure. The considered parameters were: HPC type employed in the joint (ultra-high performance concrete (UHPC) and engineered cementitious composite (ECC)), the ld values (15, 20, and 25 times the bar diameter (D)), and the pressurising condition applied through of post-tensioning system. The results demonstrated that specific combinations of these parameters significantly enhanced cracking resistance, initial stiffness and energy absorption. Moreover, integrating a pre-stressing system with a UHPC-filled wet joint and a developed length of 25D led to an approximate 98 % increase in ultimate load. A nonlinear three-dimensional finite element model (FEM) was constructed and validated against the experimental outcomes, yielding high accuracy with discrepancies less than 4 %. Additionally, a novel predictive equation for the ultimate moment capacity of the studied beams was formulated, exhibiting a mean error margin of about 3 %.
期刊介绍:
Case Studies in Construction Materials provides a forum for the rapid publication of short, structured Case Studies on construction materials. In addition, the journal also publishes related Short Communications, Full length research article and Comprehensive review papers (by invitation).
The journal will provide an essential compendium of case studies for practicing engineers, designers, researchers and other practitioners who are interested in all aspects construction materials. The journal will publish new and novel case studies, but will also provide a forum for the publication of high quality descriptions of classic construction material problems and solutions.