Optimizing Experimental Study Of Mortar Used For Planting Steel Reinforcement To Masonry Pagodas

Masonry pagodas are the important architectural heritage in our country. These pagods have experienced hundreds of years of erosion. In particular, the role of the earthquake, most of them appeared different degree of damage. As cultural relics protection consciousness increased, every government repair masonry pagodas in positively, planting steel reinforcement technology is used more widely, especially after WenChuan Earthquake this technology has been extensively used in masonry pagodas reinforcement. Planting steel reinforcement means that steel bar and steel plate is embedded and outsourced by mortar, formed "tower body-mortar-steel reinforcing system. In this technology, the mortar is the key repairing material, it plays three main functions:(1) repairing damaged masonry by grouting (2) binding steel and steel plate with masonry into a whole (3) protecting the steel and improving the durability of steel. Based on the related mechanics experiment and durability test, and combined with electron microscope scanning technique study the mortar performance that mixing different additive agent, reasonable optimize mortar formula for masonry pagodas planting steel reinforcement repair.This article mainly through adding acrylic-emulsion mixing agent, polypropylene fiber, UEA expansive agent thereof to studying the effect of mechanical properties and durability of the cement mortar and through the relevant test and analysis, summed the various proportion of mortar performance, optimizing the applicable formula for masonry pagodas repairing. The results show that:1, According the experiment discovered, epoxy resin can effectively increase the compressive strength of mortar, adhesive strength and durability; air-entraining water-reducing agent can improve the carbonation resistance of mortar and freezing-thawing resisting ability, but it also makes mortar strength decreased.2,26%～28%acrylic mortar have better bond strength, carbonation resistance and freezing-thawing resisting ability;11%～12%polypropylene fiber mortar freezing-thawing resisting ability is good, and the brittleness of mortar has good improvement;8%～10%the UEA expansive agent has good bond strength.3, Based on the electron microscope scanning, and the software analysis, the porosity of mortar can influence the mechanical properties of mortar, carbonation resistance and freeze resistance performance closely, and most of the mortar, the lower porosity can make its strength and durability are relatively good, but air-entraining water-reducing agent produces bubble inside mortar, due to air bubbles which is even, independence, closed, makes the carbonation resistance of mortar and freezing-thawing resisting ability have improved.4, According to the results of the test,mortar used for planting steel reinforcement can use different formulations according to the different function requirement.Mortar with aie-entraining water-reducing angent, acrylic mortar and UEA expansive agent mortar can be used as grouting mortar; Acrylic mortar, UEA expansive agent mortar and epoxy resin mortar can be used as bonding mortar; Epoxy resin mortar, acrylic mortar,mortar with aie-entraining water-reducing angent and polypropylene fiber mortar can be used as protection mortar.