The Evolution of Concrete (Part 3): Submerged in Mud and Its Compression Strength

Abstract

This paper discusses the microstructural degradation mechanism of slurry submerged concrete and its compressive strength. This is based on an experimental study in the basement of the Lampung University Teaching Hospital in Indonesia. Samples were taken using four core drills in the basement under protected conditions and submerged in mud for compression testing. The core drill was taken for SEM and EDX testing. Compressive strength data is processed using ASTM E178-02 standard practice for dealing with outlying observation. EDX data for both types of concrete conditions that describe the dynamic viscosity of each chemical element are compared and linked with EDX data which states atomic mass and SEM. From this relationship, the mechanism of degradation of concrete submerged in mud is sought by studying literature. The results showed that the compressive strength of concrete was submerged in mud for 10 years, only 50% of the compressive strength of protected concrete. Degradation is caused by processes series of water infiltration, oxidation of the surface water that accompanies the immersion of the mud, immersion pressure which changes the atomic structure and density of Ca and the depletion of portlandite which is then followed by the release of Ca from CSH, the appearance of Fe³⁺ which makes structural changes, increased porosity. The right way to prevent concrete from degrading its strength is to make the concrete a minimum of water permeable and protect it with a waterproof layer.

Keywords: concrete, compressive strength, evolution, microstructure, submerged in mud

DOI: 10.7176/CER/14-4-03

Publication date:June 30^th 2022