Jesús Mínguez

This study characterizes the sequential flexural fatigue behavior of fiber-reinforced concrete (FRC), in which two damage mechanisms occur in sequence: (i) matrix fatigue up to cracking, followed by (ii) fiber-matrix bond fatigue. A simple criterion is proposed that, based on the relationship between static strengths (fLOP and fR) and the maximum cyclic stress level (σfat,max), allows anticipation of this sequential behavior. When σfat,max is below both fLOP and fR, the cyclic creep curves (defined as the maximum CMOD per cycle versus the number of cycles) display two concatenated inverted-S segments, reflecting the two damage processes.The method is validated through an experimental program on three FRCs with fiber contents of 0.3%, 0.6%, and 1.0%, subjected to flexural fatigue under constant stress levels. The results confirm that the proposed criterion correctly discriminates between the general case and particular cases in which only one of the two mechanisms operates.In addition, the Sparks–Menzies relation between the slope of the central segment of the cyclic creep curve (dCMOD/dn) and the fatigue life (N) is extended to derive closed-form expressions that estimate, with high accuracy, the number of cycles to matrix fracture (Nm) and the remaining cycles to final failure (Nf–m). This tool provides a practical basis for assessing accumulated damage and optimizing the design and maintenance of FRC structural elements subjected to cyclic loading.

Information about the paper titled "DEVELOPMENT OF SERVICE-LEARNING BASED PROJECTS FOR THE IMPROVEMENT OF PUBLIC INFRASTRUCTURES IN BURGOS (SPAIN)" at IATED Digital Library

Information about the paper titled "IMPLEMENTATION OF SERVICE-LEARNING METHODOLOGY TO BACHELOR'S DEGREE IN CIVIL ENGINEERING: A CASE STUDY AT THE UNIVERSITY OF BURGOS (SPAIN)" at IATED Digital Library