Quantification of Chlorides and Sulphates on Concrete Surfaces Using Portable X-ray Fluorescence. Optimization of the...

Area of Science:

• Materials Science
• Civil Engineering
• Analytical Chemistry

Background:

• Reinforced concrete structures require accurate pathology assessment for effective repair.
• Surface contaminants like chlorides and sulphates are critical factors in concrete degradation.
• Traditional lab analysis of concrete samples can be time-consuming and costly.

Purpose of the Study:

• To develop and validate an in-situ method for quantifying surface chlorides and sulphates in concrete.
• To assess the accuracy and efficiency of portable X-ray fluorescence (XRF) analysis for concrete surface contaminants.
• To determine the optimal number of measurements for reliable error margins.

Main Methods:

• X-ray fluorescence (XRF) analysis using portable equipment on concrete specimens.
• Preparation of concrete prisms with varying concentrations of NaCl and Na2SO4.
• Monte Carlo simulations to establish the required number of random analyses for error control.

Main Results:

• Portable XRF provides accurate in-situ quantification of surface chlorides and sulphates.
• Six random analyses for sulphates and eight for chlorides ensure errors below 10% in 95% of cases.
• Coarse aggregate presence showed no significant influence on quantification accuracy.

Conclusions:

• Portable XRF is a reliable tool for in-situ concrete surface analysis.
• The method eliminates the need for laboratory sample transport, reducing inspection costs.
• Accurate, on-site data enables more efficient and cost-effective repair strategies for concrete structures.