Abstract: The present invention disclosed a concrete water reducer by grafting of lignosulfonate with carbonyl aliphatics and its preparation method. A technical solution of the method is as follows: compound proportioning of the concrete water reducer (weight) is: carbonyl group aliphatics:lignosulfonate=1:(0.75-1). The said concrete water reducer by grafting of lignosulfonate with carbonyl aliphatics is prepared through following process steps: controlling the temperature of aliphatics water reducer at 95-100° C.; dropping lignosulfonate into said aliphatics water reducer; conducting graft copolymerization reaction at 95° C.-100° C. for 2-5 h and obtaining lignosulfonate modified and grafted aliphatics concrete water reducer. The method of present application is simple, low cost and friendly to environment. The water reducer has good water reducing effect and can reduce colour aberration of concrete and thus be applied broadly.

Abstract: Taught herein is a signal-free roadway interchange, comprising a plurality of longitudinal lanes and a plurality of transverse lanes intersecting the longitudinal lanes; wherein an intersection between the longitudinal lane and the transverse lane is grade-separated, one of the longitudinal lane and the transverse lane ascends gradually at first, crosses a lane perpendicular thereto, and descends gradually to form a viaduct; a plurality of right-turn lanes are disposed at four corners of the intersection, for connecting to the transverse lanes or longitudinal lanes perpendicular thereto; a plurality of pedestrian bridges crossing the longitudinal lanes and the transverse lanes are disposed at four outer corners of the intersection; and a pair of pedestrian channels respectively parallel to the longitudinal lanes and the transverse lanes connect every two opposite pedestrian bridges.