In order to solve the problem in the strength decline of elastic concrete,its modification treatment was carried out by using coupling agent and emulsion rubber.Meanwhile we studied its physical and mechanical properties.The results were as follows: With the increase of colloidal particle's content,the physical properties of elastic concrete decreased significantly,but deformation increased.While the mechanical properties,impact resistance and wear resistance all greatly increased with the addition of coupling agent and emulsion rubber,and the compressive strength,wear resistance enhanced by 17.3%,12.7% respectively within 28 days and tack free time shortened,which effectively dealt with the difficult problem of the decline in the strength of elastic concrete and construction.Meanwhile,we put forward the construction technology and application prospect of bridge expansion joint engineering.The conclusions above have very important reference value for the further study and appliation of this new elastic concrete in expansion joint engineering