Ultrasonic descriptors of accelerated carbonation in Portland cement pastes: time-domain, phase, and harmonic features validated by FTIR

Description

This dataset contains the experimental and processed data associated with the manuscript “Ultrasonic descriptors of accelerated carbonation in Portland cement pastes: time-domain, phase, and harmonic features validated by FTIR”. The dataset includes ultrasonic through-transmission measurements obtained from Portland cement pastes with water-to-cement ratios of 0.4, 0.5, and 0.6 subjected to accelerated carbonation at 4% CO2 for up to 120 days. The data support the analysis of normalized cumulative energy, total signal energy, energy-spreading duration, phase-slope evolution, and relative third-harmonic content. FTIR data used as an independent indicator of carbonation progression and TGA data used as an initial reference for CaCO3 content are also included where applicable. Processed datasets corresponding to the figures reported in the manuscript are provided together with a README file describing the organization of the files and the relevant variables.

Steps to reproduce

Ultrasonic signals were acquired in through-transmission mode using 500 kHz longitudinal transducers. Signals were digitized at 50 MHz using identical acquisition settings for all measurements. For each waveform, normalized cumulative energy was calculated from the squared signal amplitude. The empirical parameter μ was obtained by fitting the normalized cumulative energy using F(t)=1−exp(−μt). Energy-spreading duration was calculated as the time interval between 5% and 95% of normalized cumulative energy. Frequency-domain quantities were obtained from the FFT of the recorded waveforms. The unwrapped phase spectrum was fitted over the frequency interval specified in the manuscript to obtain the phase-slope descriptor. The relative third-harmonic descriptor was calculated as H3=A3/(A1)^2, where A1 and A3 are the amplitudes of the fundamental and third harmonic, respectively. FTIR carbonate-band measurements were used as an independent indicator of carbonation progression. Additional experimental details are provided in the associated manuscript.

Institutions

• Instituto Politécnico Nacional

  Mexico City, Mexico City

Categories

Funders

• Secretaría de Ciencia, Humanidades, Tecnología e Innovación

  Mexico City, Mexico City

Licence