Heat-contraction and cold-expansion medium and small bridge seamless retraction device and construction process thereof

The invention relates to a heat-contraction and cold-expansion medium and small bridge seamless retraction device and a construction process thereof. The seamless retraction device comprises beam bodies. Retraction seams are formed between the beam bodies and filled with heat-contraction and cold-expansion mixtures. Upper closing supporting steel plates and lower closing supporting steel plates are connected to the upper sides and the lower sides of the heat-contraction and cold-expansion mixtures correspondingly. The upper side of each upper closing supporting steel plate is coved with a bituminous concrete laying layer. The construction process comprises the following steps that firstly, the width of the seams is designed; secondly, the beam bodies are cut; thirdly, the retraction seams are cleaned; fourthly, the lower closing supporting steel plates are installed; fifthly, lower bolt holes are drilled; sixthly, the heat-contraction and cold-expansion mixtures are poured; seventhly, the upper closing supporting steel plates are installed; eighthly, upper bolt holes are drilled; ninthly, fixing bolts are installed; and tenthly, the bituminous concrete laying layers are laid. The heat-contraction and cold-expansion medium and small bridge seamless retraction device has the advantages of being attractive in appearance, long in service life, low in manufacturing cost, high in construction speed, convenient to maintain and low in maintaining cost.