METHOD OF TEST FOR FLEXURAL STRENGTH OF （挠曲强度的测试方法）.pdf

California Test 524 STATE OF CALIFORNIA—BUSINESS, TRANSPORTATION AND HOUSING AGENCY March 2013 DEPARTMENT OF TRANSPORTATION DIVISION OF ENGINEERING SERVICES Transportation Laboratory 5900 Folsom Blvd. Sacramento, California 95819-4612 METHOD OF TEST FOR FLEXURAL STRENGTH OF RAPID STRENGTH CONCRETE A. SCOPE This test method describes the procedure used for determining the flexural strength or modulus of rupture of Rapid Strength Concrete (RSC) by the use of a simple beam with third point loading. Rapid Strength Concrete is used on projects where short construction windows (6 hr to 55 hr) require rapid curing (typically 3 hr to 24 hr). This test method is typically used to fabricate and test samples at the jobsite to meet traffic-opening criterion. B. REFERENCES ASTM E4 - Force Verification of Testing Machines ASTM C78/C78M - Flexural Strength of Concrete (Using Simple Beam with Third Point Loading) California Test 539 - Sampling Fresh Concrete C. APPARATUS 1. Testing machine: The testing machine shall conform to the requirements of Sections 16, 17, and 18 of ASTM E4 and Section 4 of ASTM C78/C78M. 2. Beam molds: a. Molds shall be made of plastic or other material with a low coefficient of thermal conductivity and be non-reactive with concrete containing hydraulic cements. b. Molds shall maintain their dimensions and shape under all testing conditions. c. Molds shall be mortar tight during use. A suitable sealant, such as sealing caulk, heavy grease, modeling clay, or micro-c