Quantifying Decay Due to Wet Atmospheric Deposition on Basalt

The study of building materials is important for a better conservation of built heritage. Worldwide, volcanic stones (including basalt, andesite and dacite) are among the least studied building materials. In this research, the decay of a red basalt due to wet atmospheric deposition was studied. Red basalt was exposed to artificial rain solutions, prepared from rain samples collected weekly from 2014–2019. In this research, the decay of stone-built heritage was indirectly studied emulating wet atmospheric accelerated weathering under three different volume weighted mean (VWM) compositions: global, acid and no-acid categories. Lixiviates were analyzed to better understand the deterioration mechanisms taking place inside the material. Decay was quantified as mass difference, water absorption capacity (WAC) and open porosity (OP) changes. Results show that the methodology used is suitable to research the decay of built heritage. The studied basalt is indeed prone to decay by wet atmospheric deposition. The main decay mechanisms are the washing of insoluble compounds, dissolution of minerals, salt crystallization and cation exchange. WAC and OP showed promising results of their appropriateness as monitoring variables of decay in situ. Acid conditions produce the most severe decay, but Ph effect is not as important as precipitation volume. Non-linear equations relating volume of precipitation with mass difference in red basalt are presented

Clavigero. Comunidad de saberes, núm 10: Antidoping para una sociedad adictiva

Desmitificar el tema de las adicciones y de la persona del adicto no es tarea sencilla, se requiere una nueva perspectiva que parta del diálogo de saberes y una lectura desde la complejidad, más allá del problema centrado en el consumo. La creación de puentes de conocimiento e intercambio de experiencias entre profesionales, miembros de la sociedad civil y los aquejados por las adicciones se vuelve hoy más que nunca pertinente, ya que de todas estas fuentes de saber se nutre la construcción del fenómeno adictivo en la comunidad. Esperamos que este número pueda ofrecer vísperas de soluciones y perspectivas que construyan una más amplia definición y alternativas de intervención