Abstract This study gives an example of the steps that a repair work must include to be successful. It deals with a specific building, repair material (lime mortar) and application (render), but also with the study of the repair mortar in the laboratory and on site. Firstly, the original materials of the wall were characterized to ensure compatibility with the new repair mortars. Secondly, the suitability of different mortar mixes, made with lime and calcareous aggregate, was assessed by characterizing their properties after 15 months. At the same time, the repair mortars were applied in testing panels, and their behaviour under environmental conditions was studied and compared with that of the laboratory mortars. Mortar properties (shrinkage, adhesion, mineralogy, microstructure and texture) developed differently according to the curing conditions. The carbonation degree was higher in mortars cured on site (especially those with higher aggregate content), although in both cases it depended on mortar porosity. Testing the type of application on site was helpful to define the best performance of the designed mixes and to choose the most suitable one among them, which was found to be the 1:6 binder-to-sand ratio mortar applied in both layers of the render.

The Guadix topographic depression is a Neogene-Quaternary basin located in the central sector of the Betic Cordillera at the boundary between the South Iberian margin and the Alboran domain. This topographic depression is a plateau with an average elevation of 1000 m in the northern limb of the Sierra Nevada range. The continental deposits infilling the Guadix basin span time from the late Tortonian to the Pleistocene, when a laminar calcrete developed on fine- to coarse-grained fluvial and lacustrine deposits. The drainage pattern is strongly incised (up to 200 m) below the calcrete layer. Four coeval subsamples from the top laminae of the calcrete were collected and dated by the U/Th method. The resulting date is 42.6 ± 5.6 ka, which indicates the minimum age for the cessation of active sedimentation in the Guadix basin. Using this age, we have calculated the incision and erosion rates for the late Pleistocene to present-day time span in the Arroyo de Gor, a highly incised canyon in the eastern border of the Guadix basin. The minimum incision rates in this canyon are around 4 mm/yr. We envisage the capture of the Pliocene-Pleistocene endorheic Guadix basin by the Guadalquivir River after 42 ka as the main factor triggering the formation of the present-day eroded landscape. After the capture, the combination of climatic (wet periods), lithological (soft and loose sediments), and topographic (high average altitude) features allowed the development of the present-day entrenched drainage pattern. La depresión de Guadix es una cuenca neógeno-cuaternaria situada en el sector central de la Cordillera Bética cubriendo el contacto entre el Margen Sudibérico y el Dominio de Alborán. Esta depresión topográfica es, sin embargo, una superficie elevada (sobre unos 1000 m) desarrollada en el flanco N de Sierra Nevada. El relleno continental de la cuenca de Guadix abarca desde el Tortoniense superior al Pleistoceno, y está coronado por una calcreta laminar que se desarrolló sobre materiales detríticos lacustres y fluviales. La red de drenaje está fuertemente encajada (hasta 200 m) bajo este nivel de calcretas. Se han datado, mediante el método de U/Th, cuatro submuestras correspondientes a las facies laminares situadas en el techo del nivel de calcretas más alto. El resultado de la datación de la calcreta es 42.6 ± 5.6 ka, que puede interpretarse como la edad mínima para el final de la sedimentación activa en la cuenca de Guadix. Usando esta edad como referencia, hemos calculado las tasas de incisión y erosión desde el Pleistoceno superior en el Arroyo de Gor, un cañón fuerte-mente encajado en el borde oriental de la cuenca de Guadix. Las tasas de incisión en este cañón están alrededor de 4 mm/año. Consideramos que la captura Pliocena-Pleistocena (post–42 ka) de la cuenca, con carácter endorreico en ese momento, por parte del río Guadalquivir es el principal factor desencadenante del actual relieve erosivo que presenta la cuenca de Guadix. Tras la captura, la combinación de factores climáticos (periodos húmedos), litológicos (sedimentos detríticos con escasa cohesión) y topográficos (alta altitud media) han favorecido el encajamiento progresivo de la red de drenaje actual.