The Sulphate Effect on Lijiaxia Concrete Dam (China) Gallery

Abstract

The concrete degradation is one of the most serious problems for a dam construct during the normal operation, which determines the dam service life. Hence, it is very important to reduce the extent of the dam concrete degradation for the safety of the dam normal operation. Here, Lijiaxia hydroelectric station is taken as an example, and a comprehensive method to assess the sulphate effect on dam gallery is proposed. Eleven samples in total were taken from three difference locations by the drill bore. The microstructural investigations including X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS) were conducted to assess the sulphate attack and the degradation degree. Meanwhile, the water chemical analysis was applied to reveal the mechanism of concrete degradation. The experimental and analysis results indicate that the concrete degradation degree varies with the location of the samples. The components of the concrete change and the content of SO 3 increase dramatically during degradation. Moreover, the mineral facies of the concrete change correspondingly, with the cement paste substituted by the calcite, calcium vitriol, and gypsum. The reinforcement and precaution measures are suggested based on the results of the degradation assessment.

Comprehensive Testing of Sulfate Erosion Damage of Concrete Structures and Analysis of Silane Coating Protection Effect

“…Subsequent model experimental analysis showed that the erosion of tunnel-lining concrete by sulfates is the main cause of cracking and spalling of tunnel linings [ 7 ]. A similar situation occurred at Bapanxia Dam [ 8 ] and Lijiaxia Dam [ 9 ] in the northwestern region. Sulfate minerals in the underlying rock and soil bodies came in contact with the concrete via groundwater transport, causing severe damage to the concrete structure in the projects.…”

Discrete Particle Method Numerical Simulation on The Distributions of Suspended Particles in The Flow of Ogee Spillway Structure

“…In another study of civil dam related problems, the comprehensive evaluation method by using XRF, XRD, SEM, and EDS was applied to investigate the mechanism of the concrete degradation [4]. This is supported by the study of Silva et al, where it explains that microscopy is the only technique capable to clearly identify the features associated with DEF in concrete [5].…”