12Microcracking induced by wide fluctuations in temperature affects granite quality and durability, making the stone more vulnerable to decay. 13Determining the extent of that effect is not always straightforward, however, given the excellent durability of these materials. 14 Four types of construction granite quarried in the region of Madrid, Spain, and frequently used in both the built heritage and in de novo 15 construction (Alpedrete, Cadalso de los Vidrios, Colmenar Viejo and Zarzalejo) were exposed to 42 thermal cycles (105-20º C; UNE-EN, 14066, 16 2003). Petrographic and petrophysical properties were analysed using both destructive and non-destructive techniques. Microcracking generated in 17 the granite stones by 42 thermal cycles had barely any impact on their petrophysical properties, which are the parameters normally assessed to 18 establish material quality and durability. Their petrographic properties, which are not generally assessed in this type of studies, were affected, 19 however. This study contends that petrographic analysis is needed to objectively quantify the actual quality and durability of the most highly 20 resistant materials when petrophysical studies are inconclusive. Petrographic and fluorescence microscopy, along with fractography, are among the 21 most prominent techniques for petrographic exploration. Thanks to the deployment of these techniques, mineral microcracking could be monitored 22 throughout the present tests conducted. 23The microscopic findings revealed substantial micro-textural and microstructural change in and around the granite minerals, which play a 24 prominent role in decay. The findings showed that pre-existing microcracks coalesced and generated further microcracking as decay progressed. 25Microcracking was most intense in Zarzalejo granite due to its textural characteristics determined by its high feldspar content. Microscopic 26 observation revealed that the microstructure of feldspar minerals, with their crystallographic anisotropies and secondary mineral phases, favoured 27 microcrack development. Zarzalejo granite exhibited lower quality and durability than Colmenar Viejo and Cadalso de los Vidrios granites, which 28 were more resistant to heat treatment. 29 30

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17Throughout history, different types of stone have been used in construction in Madrid, 18depending on the proximity and accessibility of the geological resources, the ease with 19 which they could be quarried and carried to the city, cut and hewn. More recently, 20 quality and durability have also weighed heavily in the selection. 21Flint, Madrid's first natural building stone, was used from the ninth to the twelfth 22 centuries. It was subsequently replaced by Redueña dolostone (which had been used 23 from earlier dates in areas closer to the quarries), preferred for its colour, workability 24 and availability and because it could be readily quarried. Redueña stone was 25 predominant until the seventeenth century. At the same time, granitic materials from 26

This work consists in the use of a 3A zeolite (K-LTA) obtained by a process of exchange of sodium for potassium (4A zeolite), synthesized from Venezuelan kaolin for the removal of Pb (II) ions from aqueous solutions by batch process mode in order to consider its application in treating industrial wastewaters. The 3A zeolite was characterized for X-ray powder diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR) and scanning electron microscopy and energy dispersive X-ray microanalysis (SEM-EDX). The metal concentration in the equilibrium C e (mg•L −1) after adsorption with 3A zeolite was analyzed using flame atomic absorption spectrometry (FAAS). The influences of the solution pH, contact time, metal initial concentration and adsorbent dosage have been studied. The retention of metal occurring at pH values around 6.5 and the adsorption equilibrium was obtained at 60 min. The equilibrium process was well described by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. The Langmuir parameters q m (mg•g −1) and b (L•mg −1) (which are related to the sorption capacity and constant of sorption energy) obtained were 14.64 and 5.42 respectively. The Pb (II) experimental uptake was about 14.56 mg•g −1 , a little smaller than the theoretical one given by Langmuir isotherm model. The regression parameters and correlation coefficients (R) indicate that the adsorption data for Pb (II) removal fit better the Langmuir isotherm model. Moreover, 0 < 1/n < 1 (1/n is 0.13), indicating that adsorption of metal ions on the zeolite, is a favorable physical process. The application of removing of the metal lead from real samples was examined by industrial wastewater samples. For all samples, the percentage of recovery was found with accuracy of more than 98%. The present work suggests 3A zeolite used as a sorbent material with relatively low cost, obtained from Venezuelan raw material; it is a candidate for removal lead ion and probably other cationic heavy metal species from wastewater.

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Granite is found in many world heritage monuments and cities. It continues to be one of the most widely used stones in today's construction, given its abundance, uniformity and durability. Quarrymen traditionally cut this rock along its orthogonal slip planes, where splitting is easier. Ranked by ease of splitting, these planes are rift, grain and hardway. Granite is traditionally quarried along the rift plane where coplanar exfoliaton microcracks coalesce developing a flat surface. This splitting surface minimizes the cost and effort of subsequent hewing. Rift plane was predominantly used on the fair face of ashlars in heritage buildings worldwide. Determining the petrographic and petrophysical behaviour of these three orthogonal splitting planes in granite is instrumental to understanding decay in ashlars and sculptures. The decay of building granite is different in each splitting plane. Alpedrete granite was the stone selected for this study based on the orientation and distribution of exfoliation microcracks and the characterisation of their implications for the anisotropy of petrophysical properties such as ultrasonic wave propagation, capillarity, air permeability, micro-roughness and surface hardness. Inter-and intracrystalline microcrack length and spacing were also measured and quantified. The findings show that the splitting planes in Alpedrete granite are determined by the orientation of exfoliation microcracks, which as a rule are generally straight and intracrystalline and determine the anisotropy of the petrophysical properties analysed. Splitting planes are the orientation that should be applied when performing laboratory tests for the petrographic and petrophysical properties of building granite.

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