CONCRETE V. MACADAM

Dominion, Volume 12, Issue 246, 11 July 1919, Page 8

CONCRETE V. MACADAM

EXPERTS REPORT ON PALMEESTON EXPERIMENT, 3 ■ '■ (From Our Special Correspondent.) " . Palmerston North, July 10. The.Kairanga County Council contemplates.going in for improved methods in toad:construction, but'so tar it has been uiiablo to choose between .the respective merits of'concrete and tar macadam. Two experimental pieces of road wero laid down iin the county about a year ago, one in concrete and the other in macadam. At a meeting of the council Messrs, Toogood and Alair submitted a comprehensive report on .the'concrete experiment on Kangitikei Line, which was carried out by Councillor Craw a year «igo. The report stated that they were favourably impressed with the. 'surface ■appearance of the road, except for pitting caused by driftwood in the river shingle having worked to the surface (luring the process of laying the concrete, and ,the covering film of mortar 'having been' worn away. The signs of .wear weje no greater than usually found. in ■ this class of road, but they wero not prepared to recommend further, work on the t=ame, lines, without an extensive lest. Both engineers were strongly of the opinion that before deciding upon the construction of concrete.roads the council should decide .whether it intended to countenance or on the other, hand discourage by the moans within its power heavy traction-engino traffic. This was important, because in considering the construction of concrete- roads the question of width of wheels, weight of load, and traction-eiijuno traffic must be taken into account. Tho class of road under review would be suitablo for twelve-ton loads on suitable tyres, but not for the heaviest form of traffic. Mr. Craw's road would require a carpet of bituminous compound in a few years, but this was used with "all concrete roads. „The vexed question as to what the experiment actually cost was settled by tho engineers, who estimated that it-had cost

Mr. Craw ,£213 to lay down (ho f-ve , 'chains of Toad in concrete. Ordinarily, .' ihowevor, they considered that it would cost more than this sum to construct Ibis olass pf,i;oad. At tho next meeting of tho, rt c'oujt'cll Messrs. Mair and Toogood submit a report,; on: :the tarredmacadam experiment.