MAKING GOOD ROADS.

Auckland Star, Volume XLVIII, Issue 126, 28 May 1917, Page 7

MAKING GOOD ROADS.

CONCRETE FOR PERMANENCE. The question of permanent roads, especially for country districts, is of particular moment at a time like Lite present when the rain falleth not only upon the just and unjust, but does it every day. .Reference has been made ou more than one occasion in t.i. paper to the development of the concrete road system in the United States. The fact that in tiie Auckland district there 13 plenty of lime and shingle obtainable, should render it comparatively easy, and at the same time cheap, to lay down permanent ways in concrete. Tile value of good roads is becoming more and more pronounced since tho present war has been in progress. Over ,1.000 miles of roads were laid in co.creie in the United States within the pa_t two years, and it is claimed that it was the fact of the good roads that enabled the French Army to be rushed up in time to save Verdttu. Of courj-i the initial cost of laying down a concrete road ie heavy, but against that has to be set the immense gain in the future.. In the United States it has been found that once a concrete road is properly formed the cost of maintenance ranges from £5 to £lo per ruiic per annum, according to the traffic. It is asserted ihat metalled and shingle roads in New Zealand even for light traffic, rtm_ up to £-00 per annum per miW. and in other cases up to four times as much where the road is much used. Another great saving where the roads are good is in the cost of repairs of vehicles. In Wayne County, Michigan, U.S.A., where many miles of concrete roads have been in use for eight years, they arc stated to be without the semblance of a rut, and not a section of 25 feet has liad to be remade. In VVanganui some few years ago a section of road was laid in concrete six incites deep for a width of 18 feet, at a cost of ti/ti per square yard. After bring coated with various tar compositions this road stood without further attention for two years. The cost of repairs in two and a-half years was under fourpence per square yard, and this was largely due to the replacing of tar compounds. In Auckland City so far Durham Street and Little Queen Street have been made in concrete.

One advantage claimed for concrete roads is tlu. absence of slipperiness, as there is always a gritty surface which gives a grip for horses' hoofs and wheels of vehicles. In the United States concrete roads laid on 5 per cent and 18 per cont grades have proved satisfactory. The first national conference of concrete rond buildnig was held in 1914. The second, which took place last year, laid down a brief summary of fundamental principles to bo observed in the construction of concrete roads. The first point is that draining the roadbed is vital, the sub-grade must be of uniform density and compacted, aggregates must be clean, hard and tough, fine aggregate (sand) should be coarse and well graded, a rich mixture should be used, and the materials accurately proportioned and thoroughly mixed. Sloppy eoncrcto should not be used. It is almost needless to add that it is essential that concrete must be protected from rapid drying, and should not be opened too soou for traffic