Study On Modification And Mechanical Properties Of Epoxy Structural Adhesive For Building Construction

Old buildings,such as ancient buildings and masonry structures in rural areas,are becoming more and more serious as time goes by.In recent years,the problem of reinforcement and restoration of old buildings has been widely concerned by the industry.Epoxy resin is widely used as a new building structural adhesive.However,there are many shortcomings in the application of epoxy resin structure adhesives,such as low strength,large brittleness,low modulus of elasticity and poor working performance.Therefore,it is necessary to modify the epoxy resin structural adhesive to have high mechanical and functional application value.In this paper,the proportion of epoxy resin,the type and the content of the epoxy resin structure filler were controlled.The modified epoxy resin structural adhesive was modified with nano calcium carbonate,silicon micro powder(5000 mesh)and the combination of 1:1 as the filler.The different proportions of different filler pairs under the curing agent were analyzed.The influence law of the properties of the oxygen resin structure adhesive and the classification of the modified epoxy resin building structure adhesive were made.Finally,the ratio of high relative strength,large elongation at break and high modulus of elasticity was determined.The results show that the compressive strength of the epoxy resin structure is enhanced by the nano calcium carbonate.When the curing agent is 1/2 of the epoxy resin,the compressive strength of the modified epoxy resin structure adhesive with 3% and 5% content of nano calcium carbonate is slightly improved,and the compressive strength of the resin casting is 71.34 MPa when the nano calcium carbonate is 7%.The compressive strength of the base body is increased by 12.6%.The tensile strength of the structure adhesive is improved by the nano calcium carbonate with low content.When the curing agent is 1/3 of the epoxy resin,the tensile strength of the nano calcium carbonate modified epoxy resin building adhesive with 3% content is 40.24 MPa,the tensile strength of the specific base body is increased by 16.8%.The tensile properties of the epoxy resin with high content of calcium nanometer calcium carbonate have no effect on the tensile properties of the epoxy resin.Promote the role.Silicon micro powder can greatly improve the working performance of epoxy resin structure adhesive.The breaking elongation,tensile strength and compressive strength of the epoxy resin are greatly improved.When the curing agent accounts for 1/2 of the epoxy resin,the compressive strength of the 5% silicon micropowder modified epoxy resin adhesive is 77.57 MPa,and the compressive strength is lower when the content is higher than 5%.But it is still higher than the compressive strength of the matrix.When the curing agent is 1/3 of the epoxy resin,the compressive strength of the epoxy resin structural adhesive increases with the increase of the filler,and the compressive strength of the cast specimen decreases when the content of the silicon powder is higher than 7%,but it is still higher than the compressive strength of the matrix.The tensile strength and tensile strength of the modified epoxy resin structure adhesive with 3% doped silicon micro powder are close,but the modulus of elasticity is greatly improved.When the curing agent is 1/2,the tensile strength of the modified epoxy resin structure adhesive with 5% silicon micro powder is 46.66 MPa,and the tensile strength of the specific base body is increased by 29.9%.The combination of nano calcium carbonate and silicon micro powder can produce superimposition effect.The compressive strength of the modified epoxy resin structure is more remarkable,the tensile strength and elongation at break are also improved obviously.When the curing agent is 1/2 of the epoxy resin,the compressive strength of the modified epoxy resin structure adhesive with 5% combination fillers is 83.21 MPa.The tensile strength is 39.21 MPa,the strength of the specific base body is increased by 31.3% and 9.1%,the elongation at break is 4.71%,the curing agent is 1/3,the compressive strength of the modified epoxy resin building adhesive with 7% combination packing is 80.81 MPa,the tensile strength is 40.79 MPa,higher than the matrix strength 30.1% and 18.4%,and the elongation at break is 4.54%.At the same time,the addition of nano calcium carbonate instead of some silicon powder reduces the cost of structural adhesive and meets the economic requirements in engineering construction.The modified epoxy resin structure adhesive has excellent comprehensive performance,and it can meet the requirements of building structure reinforcement,and has the popularization and application value.