CONCRETE ON THE ROADS.

Kaipara and Waitemata Echo, 4 January 1917, Page 3

CONCRETE ON THE ROADS.

CONCRETE FOR BRIDGES. Full Particulars of a Most Welcome Innovation, as supplied in a Pamphlet issued by Wilson's Portland Cement Co. Auckland. (Continued from week to week.) STORY OF A WAYNE COUNTY CONCRETE ROAD. The following description of how they build their roads in Wayne County is also taken from the annual rapoit. It will prove interesting reading and serve a« an example of up-to-date methods : — After the road has be >n staked out, we prepare and shape the subgrade. doing the msjo'- portion of such work with scarifiers and graders, the hauU ing power for which is furnished by steam engines or rollers. Careful attention is given to the grade to eliminate soft, spongy places, and a ten-ton roller is used to roll it hard. To produce a good concrete road, thorough drainage is ne3essary in addition to a good sub-grade. Both proper grade and drainage are difficult to cope with in Wayue County, as the county for the most part is flat and situated in' a valley not easily drained. The subsoil is largely of heavy, sticky clay, with some loose, deep sand.

The hauling on the sub.grade is done either by teams or with large cars hauled behind a roller or other trailer. These cars each hold seven tons of stone or sand. Materials are nnloaded wherever conditions permit by means of eteam shovels, and con struction work progresses towards the baso of supplies. We stock materials in the fall so that breakdowns and car shoi'tages at the gravel pits will not interfere with spring worrc after getting under way. Camps are established wherevei necessary in which the men are housed and fed at cost.

Furnishing adequate quantities of water for carrying on the work ia a serious problem, and in many instances we havo been compelled to pump long distances. Two or threeinch pipe lines are laid to the Dearest source of supply, and the water pumped to the job by gasoline engine In building-out of Romulus this fall, water was pumped from the Huron River, five miles away. On Grand fliver Road it was pumped six miles from the River Rouge. Long hauls over bad roads and scarcity of water are big factors in increasing our costs. After the preparation of the subgrade, which is flat. 2 x 6 inch side rails, cither of metal or wood, pro tected at the top by a t»vo-inch angle iron, are staked to the line of tho grade along each side of the road. A.s tke furirs are subs quentlyused to support the templet and bridge from which the finishers work, care is exercised to get them rigid. We use a concrete mixer that travels unrler its own power-, and from which a. twenty-foot boom projects capable of being swung in the arc of a semicircle. The dumping bucket is carried out on this boom under power which -saves much handling. Tv prevent absorption of water from tiie concrete, the sub-grade i? thoroughly wet down. After receiving twelve complete revolutions in the mixer the concrete is dumped in place on the natural sub soil, no cinders, sand or other material being used on the grade. The buoKet is dumped carefully to avoid spparation of the aggregate, and to make as little shovelling as possible necessary to roughly level the concrete for the work of the templet. We use a 2:3:6 mix that i&, two cubic feet of cement, three cubic feet oil sand, and six cubic feet of pebbles. The mix is wet, and of such consistency that men working in the concrete sink lour or five inches. Clean material is an absolute requisite to securing good concrete. Our pebbles are washed and screened so as $Q be free from loam, clay, and other foreign substances. They range from onefourth to one and one-half inch, und are so graded as to reduce the voids to a minimum. Our sand is bank sand, washed and screened, free from loam, clay, etc., aud ranges in size from one-fourth, inch, to dust, with the coarser, particles predominating. Wayne, County has no stone hard enough for our purposes, and all sand and stone used are shipped from outside points.

The concrete is brought to grade and shape by the nse of a templet. This templet or strike! bo.ard is made of two.-in.eh plank, \ preferably in a single piece, the cUrvature of the under edge being made to e^ictly conform to. the finished surface of the onnorete road, whioh is crowned onefourth of an inch to the foot. On each side of each end is an iron handlo for drawing the strike back and forth. The curved edge is shod with one.-inch-.angle irons bent to the curvature ? af, the strike, giving it a metal wearing surface. The tftqgjih of the strike e^cee/ls the width of the road metal by one foot, A

B.hqulu you have anything, nice to sa about yourself, your friends, or gen« lities, seni it to the Ecii X* A. medical journal says that tall me live longer than short men. This ma bo so. Also, they are longer dea< Crafty men condemn studies, simpl men admire them, but wise men us them.—Bacon. -i