ROAD CONSTRUCTION

Evening Post, Volume CXI, Issue 68, 21 March 1931, Page 17

ROAD CONSTRUCTION

; • ■ -..' —. w t \ ■ ■ . .-...' IS THE ;^ST | :; v-a MATERIAL' ?;1 .V-.V-O

-'.-.. ■ (To tlie gditoKX1 « . ?"-'"v;j;:* .'■'•' •; ;Sir,—Many.;of: your, ireaders.jriusi;. b.a)» ■■'<}■■ received, a severe shock at the emphatic ■ statement made by tJie' Mayor jTecefitly^ that •"A lot' of; /absolute."nonsense1 ".-"was .... talked when bituminous • roads ■ WereslJaM < :,.' down. People were,told-that-thejr,would require no maintenance, but. there,.;i» '•>• no: such' thing' 'as "an ..everlasting., road; • .-■ • Bitumen requires to, be ;;maintainecl juntas '-.macadam, 'does." '':: '■'. : ' '■-''._ ..>:' C .' t_.'. ■I, with :many1 others,- received- the-am*. ..'.-'■ pres'sibri'■■■during.-the>, advocacy of the- bitu- j•'. . ininousroads campaign several years ago, • that the 'maintenance of such roads wou,ld % , : be.' practically'- nil,." and ■ that. the^saving v . accruing' i'rdin- the. adoption -of .the .".bitiy:- v ; ) ihinous roads would relievel the ; ratepay* ' ,' ers of. a- considerable 'burden ' ini'vmain- A tenancei charges. No: doubt-■ up to[.' da W .'..' . ■', this ,is quite < correct, and the-large %uni vhich 'would' formerly' have been speri| in ■~; maintenance has. undoubtedly beenisaved;-..., but there is7no gainsaying the. fact' that ' t •very: year .now the hiaintena'nce '-of1 our : . Expensive bitumen pavements-is,becomjpj ; cn1 increasirigly. large -item, : . and furtnjsly the -'- surface Conditions of'some of ..these ' ; roads is giving , causes ,6i ■-. considerable «nxiety: to;our. Engineers./^ ;:;;:' :■<■■■^, ■■..'•.: '..'Recently, I-1 ;had -. the ;. pris;leg».. during ' my ' travels," , to :come" in : contact: vi Tifjth some of 'the best authorities on road congtructiqn, • both 'in Britain and Australia, • and the information gained (seemedi;t<» r.-.., be of. such- impor'tahce as to urge .in.e^to .. lay before* the. people; here .a ■ few :of >tn« facts. Briefly, -that the^ bituminous TOade ..,-, in ■ different iparts of; .-the, world are.-nbt standing up-to the! wear;and-tear,of'.mjjd* ■ ern'traffic, and in many places are_;b«ibg ■ takenup.and concrete put;down. In,-.m« connection, I] mehtionVHolborn and Regent street in TLondon. 4 The /quegtion^-thett-; V v arises: Why should we -in New.^Zealanduse kn imported material for'iroadcpn- .-:■.,;. struction. when >we,v,have;> ;better -ma"- , terial. in our own country;? As a resul*; of investigation-and upon : ;.the _ subject, permit : me 'to'-'submitwthe.-tW- ,■ lowing :data:r— :. .:. .. ;..-! ■.•"'■ ■. -'o-8^- '-«- 'The road-over,, the' Grampians:in, bc<?t« ;< land is in Concrete 6in thick,,put:dowa r in 1925—maintenance to date, nu, exceDt. : - for ' tarring ' of '■ contraction ■ .joints..'ln;.=*' : .. «übiirb of LondonV an V experiment,. wm ■;..■ tried;of laying down, a vstrip of road.la bitumen, followed by a strip of concrete, and then a-final'strip of bitumen. The ; result -is that the concrete. lengtll'.ie per- ~-.-.-- feet, ! and; both >, bitumen: stretches:-. ib,bp. ; signs ofj disintegration. -In Chelseaj^Eng- ■' land, -there Ms' a concrete roadrput down . five years- ago,, over which 20,000-tons. ;p£ ..,-. traffic' ■ per 'day^v passes. r :J Maintenance chargeg to date \ are "practically' nU.^ :<.^ , : k I have also travelled over f a-number:.^* . concrete:roids;,in, Austraha bid^down--by ;,,-, the-penetration method,-6in;th Ick,?haym«1 ck,?haym« , no :reinforcement;; or! expansion ,. joints^n-, ■ ;; corporated in -Vifa ; construe ton. The .Qost H - of this- type "of Sroad is: comparatvve^r -.- f^JquSrytog^ men -producing gravel: and . AU 'thi -above j increased Templp^ ):■ minlmean^also -WditfwU^^W^ : f?om-the vanoas employers concerned^ factors ;gHonld>irely^ount wrfh, -• the^ers' that ;be-in !:s^USly\cpn S^er-.; , ing -the ■ question,;; especially I whem rt£# ; SLted ; that; toncrete: ; .roads,^d^°S» V or : penetration, .:.. method^e, strmiger ;and, more ; dural^ : ;v and ur the case/of penetration',cheaper> ■ in'the first: cost, than ;roads >builii;Wjtti .; ; t^aw. attention: wKch have^been made'from tfan«,to;*un« S relative coit of .bitnnftnwd.co^. cre^' roads. cTKese companapni,vl. ;contend- have beenXnnfair;i:Aß.r an : inßtance ; Sis!!l would^refer tt?«ieitend^pr the Bavinz of the Jphnsonvdle .road * f& Koback. For this' con-: : cX^pecification^aTOd^^^ndafaoj . on-which'waif to be^budt- r,* 0?"!4^? , having' ,«houlders 9mv;thwk,?ra»W:; , with^two'i^ra; rod. i»d^ •^cambered Sab?6i'f thick -^ the^owartwnforced .< Th^^^^iPSfe ■: tion calledifor on^-a;3Hm «lab .>*«*.**■ tiickened edges.'-; The pnees .worked- out Srwdffiy::lZs.Td.per square . for concrete and 9s for ;bitumen.-.^,^ -If is interesting^ to. note that^in^th* ,; United States of; America a: speaficatiea for a.bitumen road for moderate -to, heavy ; traffic calW^or^?invroadi'•wtile^we^ ■ New .Zealandiare content; to -lay the-mere 3%in, with .the inevitable result that .with-M-a few yearsVof the roads .bemg.-con-: - structed, thei question; charges is,looming large : before the. aUth- . °1iJ eview 'of: the|;fact. that/the^acada;* r,. portions of the'Hutt rbad;are,.to ; beitrea* .-; ed; with a . concrete v foundation, upo* which'a 2in cushion of; bitumen .wrfl^b* ; laid, may I sugkesfithat a section; of,th» ; work be finished jinVplain concrete for t(i« purpose of experimenting :as.,tp,::the_nece* sity of''having .such a cushion;;!:;.. feel . sure that had the, Hutfc.road been'laidti# f cdncrete ofiginallyj there would, have beef ; practically^ no \maintenance. chaTges,^*n* tfie. surface-would ,'Tiave .been as. : gpodi to- ' ... day as when itwas laid..-:; ... ';-?.^' ■'•■< '■:'■.:.. in- conclusion. ■ I■■■am; -"extremely.-, gflad it* : see- that: the , City:;and Suburban .-High* ■ ways Board hav'e.decided,to: pave the-Se.a» ■ view 'road ■-. in,; plain Jconcjfefe, -and^m in* ; light of---' my .i experience overseas1 I .sin* . cerely trusit that '■.; this ;is .the:.b«nnningf ,'-;: of-a policy of concrete roads in/,'Wellihg i '-;=:■ toni—-I am.'etc, ? "}■ ■-:-:.;■ ■/^•t:':' '."•'■« •■':.,.- ---■■;. ~v.' ;?; ;--;:\george|'Av!::m'lean; : ,;. - <;