High performance thermal insulating composite materials can be produced with mineral binders and hydrophobic aerogel particles through a hydrophilization process for the latter with surfactants. The present study is focused on the development of aerogel/calcium sulfate composites by the hydrophilization of hydrophobic silica aerogel particles through a polymer-based surfactant. Its effects on the microstructure and hydration degree are examined as well as their relation to the resulting mechanical and physical properties. Results show that composites with an around 60 % of aerogel by volume can achieve a thermal conductivity \30 mW/m 9 K. Interestingly, a surfactant addition of 0.1 % by wt% of the water in the mixtures provides better material properties compared to a surfactant wt% addition of 5 %. However, it has been found around 40 % entrained air, affecting the material properties by reducing the binder and aerogel volume fractions within the composites. Moreover, gypsum crystallization starts to be inhibited at aerogel volume fractions [35 %. Towards material optimization, a model for the calculation of thermal conductivity of composites and an equation for the compressive strength are proposed.

The Church of the Company of Jesus in Quito (1605–1765) is one of the most remarkable examples of colonial religious architecture on the World Heritage List. This church has multiple constructive phases and several interventions with no clear record of the entire architectural site, including the historical mortars. A total of 14 samples of coating mortars inside the central nave were taken, with the protocols suggested by the research team and a comparative sample of the architectural group that does not have intervention. The analysis presented in this paper focuses on mineralogical characterization, semi-quantitative analysis by X-ray diffraction and scanning electron microscopy with microanalysis of the samples. The results showed the presence of volcanic aggregate lime and gypsum, used in lining mortars and joint mortars. Mineralogical and textural composition data have allowed the mortar samples to be relatively dated.

Este artículo tiene como objetivo profundizar en la caracterización de los morteros de revestimiento en la arquitectura colonial de Quito de los siglos XVI, XVII y XVIII. Se parte del supuesto que durante la colonización hubo aportes locales y europeos en la construcción de la arquitectura religiosa de esta ciudad, los resultados que hoy están a la vista son testimonios de este proceso. El análisis de las características compositivas de los morteros, cuyas muestras provienen de los edificios que hoy conocemos, contribuyen a perfeccionar de alguna manera el rompecabezas de la historia, todavía incompleta, ya que las destrucciones producidas por terremotos, y sobre todo intervenciones de restauración o ampliación edilicia han dejado sus huellas en estos edificios.

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