Prestress loss model for ultra-high performance concrete. (1st February 2022)

• Record Type: Journal Article
• Authors: Mohebbi, Alireza; Graybeal, Benjamin
• Is Part Of: Engineering structures. Volume 252(2022)
• Publication Date: 2022-02-01
• Subjects: Ultra-high performance concrete (UHPC) -- Pretensioned girders -- Time-dependent losses -- Creep -- Shrinkage -- Predictive loss model; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2021.113645
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: UHPC time-dependent deformations and prestress losses. Creep and shrinkage of eight commercially available UHPC-class materials. Data-driven models to predict creep coefficient and shrinkage strain of UHPC. Validation of the proposed models using seven full-scale pretensioned UHPC girders. Abstract: Accurate estimation of prestress losses is a critical aspect of the design of prestressed structural elements. Ultra-high performance concrete (UHPC) exhibits distinct creep and shrinkage behaviors, but a review of the literature revealed a lack of data and a limited set of predictive models for creep and shrinkage behaviors of UHPC-class materials. To address this gap, this study collected data, developed new equations, and proposed data-driven models to predict creep and shrinkage behaviors of UHPC-class materials. The predictive models adjust the ultimate creep and shrinkage of UHPCs based on compressive strength, age, and maturity of the material at loading. Results were compared to measured creep and shrinkage of a suite of commercially available UHPC-class materials. The main objectives of this research were as follow: (1) develop data-driven models to predict ultimate creep coefficients and shrinkage strains of UHPC-class materials for different service conditions; (2) examine the current AASHTO LRFD equations for creep and shrinkage of conventional concrete and determine the applicability of parameters in the equations for UHPC-class materials; (3) compare the predictive models with measured data, AASHTO LRFD equations, and existing European recommendations for UHPC-class materials; and (4) examine the applicability of the proposed loss model by comparing the predictions to the behaviors of seven full-scale pretensioned UHPC girders.