Strength Development Characteristics Research Articles

Studies of low-porosity concretes designed for bridge deck applications: 1. Introductory remarks, mix designs, strength development, and rheological characteristics

A major concrete problem in recent years has been premature deterioration of concrete bridge decks due to corrosion of reinforcing steel. The research reported here was designed to explore the possibility of eliminating the problem by the use of low porosity concrete. A brief review of low porosity cement systems is provided. Mix design considerations for low porosity concretes are explored. The results of laboratory trials on rheological and other features of fresh low porosity concretes are reported, and compressive strength data are provided for several different low porosity concrete systems.

A discussion of the paper “studies on the hydration of tricalcium silicate pastes. II. Strength development and fracture characteristics.”

A discussion of the paper “studies on the hydration of tricalcium silicate pastes. II. Strength development and fracture characteristics.”

Studies on the hydration of tricalcium silicate pastes II. Strength development and fracture characteristics

The fracture of hardened tricalcium silicate pastes has been studied using optical microscopy and scanning electron microscopy. The path of fracture changes with the age of the pastes. In young pastes, fracture passes primarily through high porosity C-S-H gel avoiding low porosity areas where calcium hydroxide has crystallized in the pores. In more mature pastes, this discrimination is lost as the matrix becomes more homogeneous. The different modes of fracture appear to have no significant influence on tensile strength, the tensile strength depends primarily on porosity and is proportional to the cube of Powers' gel-space ratio.