Comparative analysis of the first bricks made in the New World (1494-1544)

This paper demonstrates the quality of the clays of the bricks manufactured in the New World and their low porosity through a comparative analysis of the bricks manufactured during the first 50 years of conquest and colonization (1494-1544). Samples of bricks and tiles were taken from the sites of the ruins of La Isabella (1494), Concepcion de la Vega (1502), Fort Santiago in Fortaleza of Santo Domingo (1540), and Royal Shipyards (1544). X-ray Fluorescence (XRF) indicate the elemental chemical analysis, both qualitative and semi-quantitative, of the elements included between fluorine and uranium. The results of the chemical analysis of the case studies are shown in Table 1. The mayor percentage of oxides of chemical composition of the five simples are the following: SiO2, Al2O3, Fe2O3, MgO and CaO typical in a handmade brick. According to some authors, clays suitable for handmade brick should contain Silicon dioxide or Silica (SiO2) between 50-60%, aluminum oxide or alumina (Al2O3) between 21-28 %, Iron (III) oxide or ferric oxide (Fe2O3) between 3-8%, magnesium oxide (MgO) between 2-5%, calcium oxide or lime (CaO) between 1-10%, and other elements. With the X-ray Diffraction (XRD) was identify the qualitative identification of the mineralogical composition of a crystalline sample and indicate the characteristic peaks of the quartz, albite, and calcite crystalline phases in different proportions (Table 2). The results are related to their sintering level, presented in Table 1. Porosity is a parameter that influences other properties. In this analysis is expressed as a percentage. Historic clay brick exhibit high porosity, ranging between 20% and 50%. The samples show range between 30,19 to 42,85%, so all the samples were inside the normal ranges (Table 3).