CONCRETE ROADS.

Taranaki Herald, Volume LXVII, Issue 16503, 2 August 1919, Page 3

CONCRETE ROADS.

WORKS IN UNITED STATES. An addre-s on concrete road; was given by the Mayor of Auckland, Air. J H. Gmison, at a meeting at Onohung.t last week, the Mayor of Onebnng,i, Mr. d. Park, presiding. Air. Gunson said ho had dealt fully in his previous address with the concrete work in the city, and its relations to the Alannkau road proposals. His object was to place before the ratepayers Iho latest information as to tho test and const ruction of concrete roads This ho had obtained from Air. AV. H. Hamer, enginerr to the Auckland Har hour Board, who had recently returned from America. Air. Hamer had cartied out more •concrete work than anyone else in New Zealand, and in IhO-f introduced the system of concrete construction of the Auckland wharves. He was therefore, an authority on tho ■subject, and well qualified to apeak of t-hc most modern methods of concrete work in the United Stater Air. Hamer found that in California, for concrete roads throughout the State, the following loans were authorised:— 11)00, £3,000,000; 191.5, £3,000,000. These two loans had been practically expended ,and a further loan had been authorised of £7.000,000. There were ■ISOO miles of concrete roads in./ the State, The general practice had'been to form a 2-lft. subgrade, 15ft. wide, of concrete to a thickness of 4Jin., leaving 3ft."shoulders on either side of the concrete. In many parts oiled crusted rock was topped off on the concreting. 'i’lie cost of this in the past l ad been approximately £2200 a mile. Four to four and a-half inches was the thickness of concrete laid generally throughout the State of California From San Francisco to Los Angeles, a distance of 4-11 .miles, there, was a concrete road of 45 inches standing excellently. Tar-topping was formerly used, hut the concrete was standing so veil that tho use of the former had been discontinued. CALIFORNIAN CAR TAX. In California there was a motor car tax of £2 a car a year. Air. Gitnson said local bodies in New Zealand had no power to levy such a- tax, but he hoped the municipal conference would adopt the remiiCfavouring one. Besides aiding local bodies in their road construction work ; the tax would result iu a boon to motorists.

Engineers in California advised Mr. Hamer that the interest and cost of maintenance of concrete roads was less than wator-bound roads. The counties spent annually £4,000,000 on inaintenanco*of roads. Shingle concrete was found to bo not successful and had been abandoned in favour of cube chips. The cartage eontracls in California over j these roads had dropped from 265 to j 12 cents per ton a. mile. With the 1909 ; loan of £3,600,000, 2950 miles of con- j Crete were laid, 4Jin. thick, at a cost | of £1240 a mile. j In one day 650 ft. of concrete, 15ft. | wide, was laid by 20 men, whose wages ' were £1 Is a day. The cost of this I was about £4OOO a- mile, including til- ) liners for the valleys, which' had been j considerable, hut on flat sections the | cost had run out at £2200 a mile. All I the concrete roads iu Redwood City, California, wore 4tin. thick. They ; I,ad started with 6in. Experiments had been so successful that they wore dropping into line with other centres, and now generally adopted 45in. In 1916. | in another centre, test speeds were ; hold as follows:—l6s miles on concretc, 45 miles on earth, and 91 miles on gravel, while the oil consumption on concrete was only half that on gravel. In Seattle, right in the heart of the city, Gin. had been laid, with 25m. of: sheet asphalt. The engineer of Seattle . stated that ordinary concrete 6m. thick made as nearly a perfect road as conk, be made, and that they were now a ban- , douing any topping on the concrete, not even asphalt or tar, as the results with j the concrete had boon so good. They , were very particular about the grading . of their sand. • . , 1 Now York had just appropriated a , loan of £20,000,000 for roads, and a ; vigorous policy was now being launched j there, in furtherance of the concrete , roads agitation. In other parts of the | State they were carrying out concrete ; woik four inches thick at 3s and 4s a ; square yard, in many places no metal at all being used as a foundation. im> concrete was simply laid on solid eartn surface after being rolled. In Seattle there wore many miles of streets laid off in concrete.