CIVIL ENGINEERS

Dominion, Volume 11, Issue 132, 21 February 1918, Page 6

CIVIL ENGINEERS

ANNUAL-CONFERENCE

THE ROADS OF THE FUTURE

The annual conference of tho New Zealand Society of Civil Engineers was resumed in the Concert Chamber yesterday morning. Mr. R. S. Rounthwaite read an interesting paper on ''Wood Pavements," based chiefly on English practice, and dealing chiefly with the methods that were adopted in the Oid Country to pi'event expansion, a matter of serious moment in laying down wood-blocking in the confines of city streets. In the course of a discussion, that followed, Mr. A. J. Paterson (Wellington) said that the Wellington City Council had experienced trouble lately through tho abnormal expansion of sections of the wood-blocking at Courtenay Place, which was being rectified at the present tiine. y IIe had come to the conclusion that the expansion in the case of grey gum and brush box blocks was considerably .greater than in jarrah blocks, mid suggested that the vaiying characteristics of the timbers used may lie due to the different territories, longitudinally, that they came from. The grey gum and brush box blocks caine from the east coast of Australia, whilst jarrah came from the extreme west Concrete Roads. Prior to the adjournment, tho Concrete Roads Committee, which had met during the. morning, reported as follows: — "i'our committee view with regret the fact that local authorities in this country have not been able to adopt this (concrete) class of road construction to such an extent as to give its members an opportunity to gain actual experience on which to base a standard specification. Tho basic principles of concrete road construction were all covered in the paper, and the discussion thereon, at last year's annual meeting. In view of tho fact that the literature on tlie subject is available to all engineers interested either in magazines or text books, your committee consider that their duties should be on the lines of collecting and reporting on actual construction done in this During the la.st twelve months this lias been of a very limited amount. The AVellins;ton City Council laid 1830 square yards of concrete road in Blair Street "at ,a cost of 7s. 4jd. per square yard, including surfacing. This construction was a two course work, six inches thick, top dressed with tar and sand, with expansion joints every 30 feet. The. lower course was of ii to 1 bank run gravel, upper course 3J- to ] fine pea gravel and cement, screened to uniform section and floated. AVanganui Borough has laid 3GO yards of conoreto road on Taupo Quay, five inches thick of washed gravel .concrete in the proportions 3, 2, arid 1, single course work, h'ujshed as above, but not tarred. This cost 6s. 10d. per square yard', and after being under traffic for eight months has been carpeted with 1J inches of fine tar macadam and " sealed with a tar compound, making the total cost 9s. 3d. per square yard. Some few hundred squaro yards, it is understood, have boon laid in Napier, and a considerable area in Auckland, but regarding these no data are to hand, These areas and those previously laid have not been down long enough to warrant any expression of opinion for or against this method of construction, nor can the maintenance costs be definitely ascertained for the same reason ; but your committee is uuam'monsly of opinion that carpeting in, some form is necessary. This carpeting, or ! protective coat, should be as thin as possible, -and of the indestructible material obtainable. The extent of these areas is insignificant in comparison with those under construction in America, where the results have evi-! dently encouraged the engineers and i local bodies to adopt concrete road con- I struction so extensively. The high j proportion of motor traffic iu that j country demands a good clean, smooth surface. Engineers in this country recognise that the time has arrived when similar improvements must be carried out here, and that such will tend to economy, both to tho local bodies interested and also to road users. The demand has not yet Been made to a sufficient extent to influence public opinion in this direction, but the time is rapidly approaching when local bodies will have to take steps to meet the position. Owing to the growing importance of road construction, your committee recommend that a :ennauent elective Roads Committee be set up to collect and tabulate data, and report annually to the society at the general meeting." The report was adopted. The recommendation to appoint a permanent elective Roads Committee was left to the new council, which will meet tomorrow. After the lunoheon adjournment papers wore read on "The Hawera Borough Loan Works —Construction of Tar Macadam Roadways and Footpaths," ! by Mr. John Sturrock; "The Treat-1 ment of Metalled Roads iu Eltham I County," ,by Mr. F. Basham; and "Notes on Road Construction in the Orchard District Between Nelson and Motueka," by Mr. J. AV. Sponce.