Process of dissolution: the water attacked the hardened concrete causing leaching of lime, due to soft water. Rainwater caused the dissolution and subsequent leaching of calcium hydroxide free, which over the years has caused the breakdown of silicates, aluminates and Ferrites until all the lime has been extracted from the hydrated products and is as residual silica, alumina and ferric oxide hidratad, rich in water and without any resistance. Calcium bicarbonate is soluble causing that the sealing effect disappears and reacting in areas rich in compounds, causing new reactions whenever there is water. Speaking candidly UAH Baudry Lab told us the story. Another agent is sulphate present in some places water increases reaction, solid salts in groundwater at the time of drafting, provoked their sulfates respond, causing the formation of gypsum and trisulfa calcium aluminate, causing the expansion and destruction of the concrete, which will increase their presence (trisulfa-calcium aluminate) alongside plaster aggregates in concrete and underground waters. The presence of other sulfates as sodium, and magnesium, contributed to its deterioration, as well as the action of important magnesium chloride is the sea water used in certain moments of the execution. Performances: Initial aspects include: supported slabs in four edges, and in two directions work, whose main reinforcement is in two directions, the steel used is 12 mm, not to appreciate if the all the bottom brace comes to props, if there are any parts found in the cut steel or have bayonets since landslides are occurring to one-third of the light. Bars can save by cleaning with metal wire brushes, and Moreover there is presence of shoddy concrete appreciating stones seated in the lower level for lack of fixed and with large et108. There is no presence of arrows, or push-ups in slabs that exist, not bending moment, nor failures in braces.
The roof cover based on enrajonado, and sealing with very poor state of conservation, flooding in some areas, non-existence of splitters and earrings for their evacuation. Joints have erosion problems between racillas and problems of waterproofing parapets, and rainwater gutter without protective mesh. By what must undergo to demolish all the enrajonado and the sealing, since for this cause is It has affected all the structural elements. Rehabilitation: Is necessary to proceed from eliminating all coatings that are loose or detached in the entire area of the slab that is flabby, cleaning with wire brush and hammer steel (in our case does not exceed 20%, or slabs, or stairs.) Using on the roofs of the balconaduras antacid slabs with antacid mortar and their boards. You must raise the entire roof and clean the concrete, put it at the level, place a layer of felt, a layer felt impregnated in asphalt, place a layer of asphalt mortar, placing mortar for racilla, and then place the racilla with a good melt. You must coat the concrete detached with a type chicken mesh give points of mooring or welding to steel in view, and then apply a layer of products such as SIKA, or apply a mortar with projection (genite-shatconcrete), large density, using resistant cement and not possible to use it with soluble glass, applying it cold or hot with a brush in several layers on the surface of the concrete to protect. This type of work is the only way to preserve the old Presidio model in good condition, their slabs will become one of its ships in elementary school, thus be saved.