Assessment of Strength Development at Hardened Stage on High-Strength Concrete Using NDT

Applied Sciences

Taegyu Lee¹  Jaehyun Lee²  Hyeonggil Choi³ 

[1] Department of Fire and Disaster Prevention, Semyung University, 65 Semyung-ro, Jecheon-si, Choongbuk 27136, Korea;Department of Safety Engineering, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, Korea;School of Architecture, Civil, Environment, and Energy Engineering, Kyungpook National University, 80 Daehakro, Bukgu, Daegu 41566, Korea;

关键词: compressive strength;    rebound value;    ultrasonic pulse velocity;    high-strength concrete;    reliability;    regression equation;   

DOI  :  10.3390/app10186261

来源: DOAJ

【 摘 要 】

This study proposes model formulae for predicting the strength of concrete by analyzing the relationships between the results of nondestructive testing (NDT) methods and the compressive strength of concrete specimens at the hardened stage. Further, NDT of concrete molds and mock-up specimens was conducted using NDT methods (rebound hammer, ultrasonic pulse velocity). The water/cement (W/C) ratios were set to 0.48, 0.41, and 0.33 to achieve concrete strengths within the compressive strength range of 24–60 MPa. The evaluation parameters included the fresh concrete properties, compressive strength (mold and core), temperature history, maturity, rebound value, and ultrasonic pulse velocity. Evaluation results indicated that the reliability of existing models, based on the rebound and ultrasonic pulse velocity, is significantly low on high-strength concrete of 40 MPa or higher, and cannot satisfy the ±20% error range. Consequently, this study proposes a regression equation of the concrete strength based on the experimental rebound and ultrasonic pulse velocity values in a 24–60 MPa range, which offers satisfactory reliability.

【 授权许可】

Unknown