Public works . d by the equalizing etifect of thestorage tanks on the traveller. The concrete is de-posited behind 60 linear feet of Blaw-Knox steel formsthat are stripped after the concrete is 12 hours old,the entire 60 feet being concreted and the forms re-moved in one 24-hour day. The concrete plant isshifted every 700 or 800 feet. The concrete mixer is of \-er\- simple construction,consisting simply of a conical receptacle the upperpart of which is open to receive the charge and thenclosed to receive the air pressure, which forces thebatch through the delivery pipe. It is believed thatthe
Public works . d by the equalizing etifect of thestorage tanks on the traveller. The concrete is de-posited behind 60 linear feet of Blaw-Knox steel formsthat are stripped after the concrete is 12 hours old,the entire 60 feet being concreted and the forms re-moved in one 24-hour day. The concrete plant isshifted every 700 or 800 feet. The concrete mixer is of \-er\- simple construction,consisting simply of a conical receptacle the upperpart of which is open to receive the charge and thenclosed to receive the air pressure, which forces thebatch through the delivery pipe. It is believed thatthe passage of the batch through the pipe promotesthe mixing. It sometimes requires as much 1,500cubic feet of air per minute. The large pipe workssatisfactorily and clogs only occasionally when theconcrete passes through standard elbows instead oflong-radius curves. At the shortest bend the wearon the interior pipe surfaces is severe, requiring re-newals everv few weeks. Importance of Restricting Motor Tiuck Loads. FORWARD END OF PNEUMATIC CONCRETING PL.\NT After having spent $600,000 in one year for the re-pairs of roads injured by excessive loads on motortrucks the State of Maryland in 1920 amended themotor vehicle law, limiting gross loads to 20,000pounds, and the maximum load per inch width oftire to 650 pounds, maximum width of truck to 90inches, maximum rated carrying capacity to 5 tons,and maximum speed per hour to a sliding scalevarying from 25 miles for a 2-ton gross load to 12miles for a gross load exceeding 6 tons. The truckload is also limited to its rated capacity. The load clauses of the law are enforced by offi-cials operating permanent road scale between Balti-more and Philadelphia and another on the Baltimore-Washington Boulevard and by an inspection partyconsisting of two inspectors, two laborers, a uni-formed policeman and equipped with four loadmotors(portable jacks) in a light automobile that travelabout on the different state roads, stopping andweighing any t
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectmunicip, bookyear1896
