AASHTO T 231-17 (2021) PDF Download

The AASHTO T 231-17 (2021) standard provides guidance on the process of capping freshly molded concrete cylinders and hardened concrete specimens, such as drilled cores. The standard defines the necessary apparatus, materials, and procedures to ensure proper capping.

The purpose of capping cylindrical concrete specimens is to provide a smooth and flat surface for subsequent testing. Neat cement is used for capping freshly molded concrete cylinders, while high-strength gypsum plaster or sulfur mortar is used for capping hardened cylinders and drilled concrete cores.

The standard outlines the specific requirements for the apparatus and materials, ensuring consistency and accuracy in the capping process. It also details the step-by-step procedures to be followed, ensuring that the capping is performed correctly.