Abstract
Rebound hammer tests and postinstalled pull‐out tests are commonly used for evaluating the compressive strength of ordinary concrete, and the strength of concrete is estimated by strength curves. However, using these strength curves to predict the compressive strength of carbon fiber‐reinforced concrete (CFRC), polypropylene fiber‐reinforced concrete (PFRC), and carbon‐polypropylene hybrid fiber‐reinforced concrete (HFRC) may lead to considerable uncertainties. Therefore, this study revises the strength curves derived from rebound hammer tests and postinstalled pull‐out tests for ordinary concrete. 480 specimens of fiber‐reinforced concrete (FRC) of six strength grades are examined. Standard cube compressive strength tests are used as a reference, and the results of various regression models are compared. The linear model is determined as the most accurate model for postinstalled pull‐out tests, whereas the power model is the most accurate for rebound hammer tests. The proposed strength curves have important applications for FRC engineering of the postinstalled pull‐out tests and rebound hammer tests.
Highlights
Among the currently available testing methods, rebound hammer tests, the core-drilling method, and postinstalled pull-out tests are the most widely used for assessing the compressive strength of concrete [1, 2]
The surface hardness and pull-out force of fiber-reinforced concrete (FRC) differ significantly from those of ordinary concrete [4, 5]; evaluation of the compressive strength of FRC using the strength curves of ordinary concrete will lead to several uncertainties
A series of experimental investigations are conducted to estimate the suitability of using postinstalled pull-out tests and rebound hammer tests to predict the compressive strength of carbon fiber-reinforced concrete (CFRC), polypropylene fiberreinforced concrete (PFRC), and carbon-polypropylene hybrid fiber-reinforced concrete (HFRC). e pull-out force, rebound number (RN), and cubic compressive strength values are obtained from the experiments
Summary
Estimation of the in situ mechanical properties of existing concrete structures is imperative for evaluating their structural quality throughout their service lives. The surface hardness and pull-out force of fiber-reinforced concrete (FRC) differ significantly from those of ordinary concrete [4, 5]; evaluation of the compressive strength of FRC using the strength curves of ordinary concrete will lead to several uncertainties. According to Yoo and Shin [21], the pull-out force is marginally affected by the steel fiber content. None of these previous investigations on the compressive strength of FRC based on postinstalled pull-out tests has fully evaluated the relationship between compressive strength and the pull-out force of FRC. A series of experimental investigations are conducted to estimate the suitability of using postinstalled pull-out tests and rebound hammer tests to predict the compressive strength of carbon fiber-reinforced concrete (CFRC), polypropylene fiberreinforced concrete (PFRC), and carbon-polypropylene hybrid fiber-reinforced concrete (HFRC). The strength curves are analyzed and calibrated. e procedures used to develop the proposed model serve as a general guideline for developing strength curves in order to predict the compressive strength of concrete
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
