The Birmingham age-herald., 1920-10-05
VETERAN ENGINEER
 REVIEWS PAVING IN
 CITY OF BIRMINGHAM
( oontinued from Page Four)

l
 of the city engineer, the city has re- gently taken over entirely the plant inspection, so that practically, only the chemical work is iona by an outsider, and it is hoped that when the labor and material mnrkets become again normal, that susf'ci mt work will bs under way to justify the cost of estab- 'ishing a city laboratory or joint city and county labor; tory. which would result not only in great savings to both the city and county, but also W ,uld tend to insure better and more uniform work.
 DISCUSSION
 It is quite evident that much of the adverse criticism occurring in the press with reference to the pavements re- | ferred to the bituminous macadam or penetration pavement laid on Cliff Road and on many of the South Highland streets and few of the North Side | streets. some nine to eleven years ago. The writer was not connected with the | city at the time these pavements were | laid, nor has there ever been street paved with this class of pavement, under l his supervision.
 | This pavement is cheaper, and when new. presents almost as good an ap- | pearance as the higher grades of btu- minous pavements, and can be so main tained for many years. provided suf- 1 flclent funds are available for it's con- stant and intelligent maintenance The writer is reliably informed that the then l city engineer objected to the extensive use of this class of pavement under conditions existing in Birmingham, where ! the first cost of the pavement is as- sessed against the abutting property. whilst the maintenance cost must be | taken care of by the city, since it was | quite obvious that the city could not possibly appropriate sufficient funds to ] properly maintain such pavements. How l ever the property owners being con- vinced that t was a good pavement and ! since 1t coss less than a third. of the | then cost of first class pavement, much 1 of it was laid. which has resulted in | considerable criticism of the city. The property owners hnve now forgotten thnt the pavement waS laid against the advice Of the city engineer. The use of this form of pavement by the city resulted in l it's extensive use by many land companies. which were then deveI- OpinG subdivisions, with more l less disastrous results. However. after all whilst these pnvements l have nos been maintained in any thing like satisfactory condition, yet in many ways it would appear l that the property owners have got l tSn their moneys worth. For the l sake Of calculating, we will assume that the average age of these pave mcnts is ten years nt the present time, which is approximately cor rect. The approximate cost was is cents per square yard, the inter
 est which at eight per cent for 1 ten years would amount to 3S 1 cents, which added to the original
 cost, AS cents. would amount to
 SC cents per square yard. as the cost i, to date to the property owners. At that time the higher grades Of bituminouss pavements would have cost him on average of $1.7O per square yard. which at eight per cent for ten years, added to the
 original cost, wo uaIdmOOf enu6.N
 original cost. would amount to S3.O6, the present cost to the
 property owners of such pavements laid at that time. Subtracting SC
 cents, the present cost to the prop
 erty owners, for the cheaper form of pavement from $3.08, and there
 remains $2.20 saving to the prop
 perty owners. So that had the cost of labor and material remained the
 same to the present time. property
 owners could now have laid for
 
 \ cost of Sl.70 per square yard, with Il 30 cents laid aside.
 | Criticism was also made of thu
 asphaltic pavement laid in the Noun tain Terrace subdivision. At the time
 this pavement was laid, the subdivision T was outside of the city limits: it wal 1 the first development in which th' | streets were paved with anything bet l ter than chert; it has been in use ovel
 fourteen years; it was the first pave
 ments of it's character (sheet asphalt) I laid in the Birmingham district.
 LAID TOO HOT
 The contractor made the then com J mon error in supposing that oul
 climate was so extremely hot that il l was necessary to lay the pavement
 very hard in order to prevent its flow 1 ing down the steep grades on the
 streets paved, consequently. the pave l ment cracked very badly and became l unusually brittle. The city has grad | ually become more strict with the | owners of the real estate developments | and now requires the same class oi 1 pavement to be laid under city in. 1 spection, which would be constructed
 were tife work being done by the city
 at the expense of the property owners
 It was also suggested that the city 1 ] the contractors for the maintenance of ! the pavements for period of years I Guarantee companies will only guar 1 antee a maintenance contract for a | period not exceeding five years, and l consequently, guarantee bonds are | rarely taken. since If an engineer can ! not lay pavement which will cost less to maintain, during the first five years of it's life. than maintenance | bond will cost, he should seek another | job. A great deal was said about poor ] foundations under the pavements. and 1 yet. in spite of the great increase in | heavy truck and other traffic, prac- l tically no damage has been done to l the foundations under the pavements | with probably two exceptions. one ir l the Mountain Terrace district. laid by I a land company, the other on Tentf l avenue, South. between Twenty -thirt | and Twenty-sixth streets, laid by ths l city. Both of these streets have beer | subjected to unusually heavy traffic 1 considering the locations, Tenth ave | nue, South, being the route of the Nor l wood buses. But whilst the writer wa, not connected with the city at tn, l time either of these pavements wal constructed, he is confident that tn, trouble was caused by the unexpected
 development of wet weather spring In the clay foundation, which did no
 show up. until after the pavement wa 1 constructed. The condition of the sub soil on these two streets, apparentl,
 was different from that on any othe
 street in the city. upon which a first
 cI,