Evening capital. (Annapolis, Md.) 1884-1910, 1906-11-15
JOINT ARBITRATORS' REPORT
PILES WITH CORES IN THEM
TO BE REJECTED.
The Report In Detail Concerning
The New Spa Bridge
Controversy.

county body and the I.auer a Harper
/ Go. over certain of the piles being
| put under the new Spa creek bridge.
| between this city and lsastport, accept
| ed the recommendations.
| Briefly the two arbitrators recon-
/ mended that ali piles with cores in
| them be rejected and all which viii
| not stand a hard test such AS was
made by the engineers on one of the
| lot. be rejected. The engineers visit
/ ed the scene of the work on Tuesday
afternoon and tested pile No. 20 in
| the manner prescribed in their report
made 10 the Commissioners today. AS
| sistant Engineer Charles Phelpes, Of
| the Baltimore Electrical Commits
sion, represented the Commissioners,
and Mr. Henri kampmann, chief en-
gineer of the Ferro-Concrete Co., of
Baltimore, was named by Lauer q
| Harper TO represent them. These two
gentlemen were unanimous in their
report. The report was as follows:
Having bean appointed arbitrators
on behalf Of your Board and of the
Lauer a. Harper Company, contractors
for the construction of the new Spa
creek bridge, respectively we beg to
submit our unanimous Judgment upon
the matters referred 10 us.
ssThese matters involve the manu-
factory and setting up Of certain con
crete pilessto form the supports of the
bridge. some of the piles have been
manufactured and certain OF them
have /. been, as we are informed,
condemned by the engineer OF your
board, the reasons for such condem-
nation being the subject matter Of
this report.
This report is the result Of direct
observations on the ground, together
with interviews with your engineer
and inspector and thescontractor' rep
resentative. We have examined the
materials used in the concrete and find
the cement, sand, gravel and stone to
be Of good quality.
In measuring the quantity Of sand
in the mixture, account should be
taken of the sand introduced with the
gravel. Our conclusion as to the
quality OF the concrete going into the
makeup Of the concrete piles is that
there is too much water used in mix
ing. This results in the water carry
ing away part OF the cement, both III
mixing and by leakage when poured
into the mOulds.
'The manner in which these moulds
or forms are set up, With tho wood
strips to form the gurrugations and
the steel for reinforcement in posi-
ton, leaves an opening only about
nine inches wide, through which to
introduce the concrete. This opening
TO too narrow TO permit of properly
placing the concrete, unless ii is
soft enough to fiji voids without lamp
ing. There is evidence of lack of
homogonity in the structure of some
OF the piles from the use OF too wet
concrete. The cement, sand and stone
are not uniformly distributed.
''(a) The properties of cement, sand,
stone and gravel in the concrete
should be accurately measured, pre-
ferably in measuring boxes of known
volume.
sob The amount of water used
should be sufficient only to form the
concrete into soft paste, such that II
may be trowelled into the form and
without free water flushing 10 the sur
| face.
a sketch is attached hereto, giving
suggestion as TO the manner Of
setting up the forms i'm order TO get
good results from the above mixture
| Of concrete. The operatives filling the
1 IOTilS Will tntn Ut III II UOoiAlOn W
know how we'll the concrete is com
pactcd as we'll as preserving tho sym
metry of the core and reinforceme mt.
There is evidence that neither Of these
| desirable qualities is at present obtain
ed with any surety.
| with regard TO the piles now on
the ground:
| Cd No pile should be driven from
which the wooden core in the center
| has not been removed. This core is
| tapering with the large end uppermost
/ and tends TO act as wedge under the
blows of the hammer in addition to
any disadvantage from the swelling
of the wood in the future.
"(2) A pile is q proper pile under
| these circumstances when ii viii
stand without injury such test as
was given pile No. 20 on the 18th
| inst This test was as follows: The
pile was ''snaked' about 100 feet,
resting upon rollers upon uneven
| runners. A lashing was made TO the
pile about one-third the length from
| the large end. and then raised until
| the SMALL end, resting upon and slid
ing along the ground, was entirely
clear of the ground and held vertically
alongside the derrick.
AS there is no way after the pile
| is made to determine its strength ex-
cept by some test short of destruc-
| ton, il seems 10 us that the test made
| is a sufficient and conclusive one.
1 The pile is tested in its weakest posi-
ton. and viii never, when in place,
/ be subjected TO such strains, but on
the contrary, viii be used in its posi-
| ton of maximum strength with the
proper cross bracing.
'sIn conclusion, we think it proper
/ to say that while the test for penetra-
| ton OF the piles)- now being applied
/ under the specifications may be a
/ good one and sufficient for wood
piles. we do not consider it necessary
10 apply such TO a test upon concrete
piles, especially after setting with
a water jet, the piles having nc
| shoe, but being square on the bottom
and with considerable area Of surface
ssThese blows with a 2,000-pound
hammer dropping 30 feet is severe
test upon pile. Although cushion
is provided between the top of the
pile and the blow, il must be re-
membered that any unevenness in tho
texture Of the cushion or any dis
placement will cause the blow to bs
unequally distributed. setting NJ
strains which may injure the pile be-
low the water line (when 1t canno
b readily detected as well rs splin
tering and splitting the head Of th'
pile.