in water or air at any ordinary temperature without checking dis-
tortion or softening,
(2) A pat of neat cement as above, placed in water, which shall
be slowly raised to the boiling point and then maintained in that
condition for three hours and allowed to cool gradually, shall not show
any signs of checking, distortion or softening. The same result should
follow exposure to steam not under pressure for three hours. This
test may or may not be cause for rejection, at the option of the engi-
neer in charge.
))• Tensile Strengtiu— (1) The briquette used in testing shall be
formed in molds of the size and form now in customary use and
recommended by the American Society of Civil Engineers, the stress
to be applied at a uniform rate of 600 pounds per minute until
fractured.
(2) All briquettes of neat cement are to be made from paste of
normal consistency in the following manner: The molds should
be filled with the paste as soon as it is thoroughly mixed and tem-
pered, the material pressed in firmly with the fingers and smoothed
off with a trowel without ramming; the material should be heaped
up on the upper surface of the mold, and in smoothing off the trowel
should be drawn over the mold In such a manner as to exert a mod-
erate pressure upon the exce)3s material. The mold should then
be turned over and the operation repeated upon the other side.
(3 Briquettes for twenty-four hours tests shall be allowed to set
twenty-four hours in moist air.
(4) Briquettes for seven and twenty-eight day tests shall be
allowed to set one day in moist air and remainder of period in water.
13— S. G.
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194 ANNUAL REPORT
(6) All briquettes are to remain In the water until they are placed
in the testing machine, except in the case of twenty-four-hour tests.
(6) Neat twenty-four-hour tests shall not show less than 126
pounds per square inch. Neat seven-day tests shall not show less
than 400 pounds per square inch. Neat twenty-eight-day tests shall
not show less than 600 pounds per square inch, and should show at
least 10 per cent, increase above the seven-day test.
tX Sand Test— Owing to insufficient data, the Committee is not
prepared to specify a sand test.
J3» Specific Gravity, — The specific gravity, determined upon dried
cement which has passed through a No. 100 sieve, shall not be less
than 3.10 nor more than 3.30. The specific gravity can be conveniently
and accurately determined by the use of Le Ohatelier's apparatus
as recommended by the Committee on uniform tests of cements.
i4, Chemica]* — Chemical analyses should show not more than 5
per cent, of magnesia, nor more than 1.75 per cent, of sulphuric
anhydride.
)5* Uniformity,— If in the tests of any given brand of cement
any sudden, irregular or wide variation from its normal action is
found, it should be withheld from use until more extended tests
shall have demonstrated its reliability.
NATURAL CEMENT.
NOTE — Only those sections of the natural cement specifications
which differ from those of the Portland cement are printed here. To make
these specifications complete, supply the missing numbers from the preced-
ing.
t. Definition* — Natural cement is a product formed of calcinated
limestone containing clay and carbonate of magnesia reduced to a fine
powder.
3« Weight* — One barrel shall contain not less than 300 pounds of
cement (West of the Allegheny Mountains this may be 265 pounds.)
Three paper sacks or two jute sacks of cement shall be equivalent in
weight to one barrel.
& Fineness* — Not less than 80 per cent, of the cement tested
shall pass through a No. 100 standard sieve.
9* Set. CD Initial set shall not occur in less than twenty (20)
minutes.
(2) Final set shall not occur in less than forty-five (45) minutes
nor more than four (4) hours.
(6) The amount of water required to make a paste of normal
consistency varies with different cements, but will be found to
be approximately 30 per cent, of the weight of the cement. It should
have a temperature of 70 degrees Fahrenheit.
lU Tensile Strengtiu— (D The briquette used in testing shall
be formed in molds of the size and form now in customary use and
recommended by the American Society of Engineers, the stress
to be applied at a uniform rate of 400 pounds per minute until
fractured.
(6) Neat twenty-four-hour tests shall not show less than 60
pounds per square inch. Neat seven-day tests shall not show less
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STATE GEOLOGIST. 196
than 100 pounds per square inch. Neat twenty-eight-day tests shall
not show less than 160 pounds per square inch, nor less than 25 per
cent, above the seven-day test.
J3. Specific Gravity* — The specific gravity, determined upon dried
cement which has passed through a No. 100 sieve, shall not be less
than 2.50 nor more than 2.80. The specific gravity can be conveniently
and accurately determined by the use of Le Chatelier's apparatus as
recommended by the Committee on uniform tests of cements.
PORTLAND CEMENT CONCRETE.
The foUowlng Specifications for Concrete were not acted upon by the
Convention for lack of time, but are considered of such importance as to
justify publication In this form:
Cement — Cement shall be Portland, either American or foreign,
which will meet the requirements of the standard specifications.
Sand. — Sand shall be clean, sharp and coarse, but preferably of
grains varying in size. It shall be free from clay, loam, sticks and
other impurities.
Stone* — Stone shall be sound, hard and durable, crushed to sizes
not exceeding two inches in any direction and freed from dust by
screening.
GraveL — Gravel shall be composed of clean pebbles of hard and
durable stone, of sizes not exceeding two inches in diameter, free from
clay and other impurities except sand. When containing sand in any
considerable quantity, the amount per unit of volume of gravel shall be
determined accurately to admit of the proper proportion of sand being
maintained in the concrete mixture.
Water* — ^Water shall be clean and reasonably clear, free from sul-
phuric acid or strong alkalies.
Mixing by Hand* (1) Tight platforms shall be provided of suf-
ficient size to accommodate men and materials for the progressive
and rapid mixing of at least two batches of concrete at the same
time. Batches shall not exceed one cubic yard each, and smaller
batches are preferable, based upon a multiple of the number of sacks
to the barrel.
(2) Spread the sand evenly upon the platform, then the cement
upon the sand, and mix thoroughly until of an even color. Add all
the water necessary to make a thin mortar and spread again; add
the gravel if used, and finally the broken stone, both of which, rf dry,
should first be thoroughly wet down. Turn the mass with shovels
or hoes until thoroughly incorporated and all the gravel and stone
is covered with mortar; this will probably require the mass to be
turned four times.
(3) Another approved method, which may be permitted at the
option of the engineer in charge, is to spread the sand, then the
cement, then the gravel or broken stone; add water and mix thoroughly
as above.
Mfadng by Madiine*-— A machine mixer shall be used wherever the
volume of work will Justify the expense of installing the plant. The
necessary requirements for the machine will be that a precise and
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196 ANNUAL REPORT
regular praportioning of materials can be controlled and the product
delivered be of the required consistency and thoroughly mixed.
GonslBteacy.! — The concrete shall be of such consistency that when
dumped in place it will not require much tamping. It shall be
spaded down and tamped sufficiently to level off, and will then quake
freely, like Jelly.
Course*^ (1) ESach course should be left somewhat rough to insure
bonding with the next course above; and if it be already set, shall
be thoroughly cleaned and dampened before the next course is placed
upon it The plane of courses shall be as nearly as possible at
right angles to the line of pressure.
(2) An uncompleted course shall be left with a vertical joint
where the work is stopped.
(3) The work should be carried up in sections of convenient
length and completed witnout intermission.
Ezpandoa Joints. — (1) In exposed work expansion Joints shall be
provided at intervals of thirty to fifty feet. A temporary vertical form
or partition of plank shall be set up and the section behind completed
as though it were the end of the structure. The partition will be re-
moved when the next section is begun and the new concrete placed
against the old without mortar flushing. Locks shall be provided
if directed or called for by the plans.
(2) In reinforced or steel concrete the length of these sections
may be materially increased at the option of the engineer.
Time. — Concrete shall be placed immediately after mixing and any
having an initial set shall be rejected.
Facing. — ^About one inch of mortar of the same proportions as
used in the concrete may be placed next to the forms, immediately
in advance of the concrete, or a shovel facing made, at the option
of the engineer in charge.
Forms. ^(1) Forms shall be substantial and unyielding, properly
braced or tied together by means of wire or rods.
(2) The material used shall be of dressed lumber, secured to
the studding or uprights in horizontal lines.
(3) Planking once used in forms shall be cleaned before being
used again.
(4) The forms must not be removed within forty-eight hours
after all the concrete in that section has been placed. In freezing
weather they must remain until the concrete has had a sufficient
time to become thoroughly set.
(5) In dry but not freezing weather, the forms shall be drenched
with water before the concrete is placed against them.
(6) For backings, undressed lumber may be used for forms.
Finishing. —(1) After the forms are removed, any small cavities
or openings in the concrete shall be neatly filled with mortar if
necessary. Any ridges due to cracks or joints in the lumber shall be
rubbed down; the entire face shall then be washed with a thin grout of
the consistency of whitewash, mixed in the proportion of one part of
cement to two parts of sand. The wash should be applied with a
brush.
(2) The tops of bridge seats, pedestals, copings, wing walls,
etc., when not finished with natural stone coping, shall be finished
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STATE GEOLOGIST.
with a smooth surface composed of one part cement and two parts of
granite, or other suitable screenings, or sand applied in a layer 1 to
1% inches thick. This must be put in place with the last course of
concrete.
(3) In arch tops, a thin coat of mortar or grout shall be applied
over the top to thoroughly seal the pores.
Proportioning*
197
â–
Parts by Volxtmb
STKUOTUKB.
Cement.
Sand.
Gravel.
Broken
Stone.
t
The proportion of the materials in the concrete shall be as specific-
ally called for by the contract, or as set forth herein, upon the lines
left for that purpose; the volume of cement to be based upon the
actual cubic contents of one barrel of specified weight
H. G. Kellet, Chief Engineer, Minneapolis & St. Louis Railway, Minneapolis,
Minn., Chairman;
W. Lr. Bbeckenbidge, Chief Engineer, Chicago, Burlington & Quincy Railroad,
Chicago, 111., Vice-Ohairman;
E. C. Bbown, Engineer Maintenance of Way, Union Railroad, Port Perry, Pa.;
M. W. CooLET, Consulting Engineer, Boston, Mass.;
John Dean, Consulting Engineer, St. Louis, Mo.;
C. F. W. Felt, Chief Engineer, Gulf, Colorado & Santa Fe Railway, Galveston,
Tex.;
W. E. HoYT, Consulting Engineer, Rochester, N. Y.;
C. Lewis, Civil Engineer, New York, N. Y.;
G. F. Swain, Professor of Civil Engineering, Massachusetts Institute of Tech-
nology, Boston, Mass., ^
Committee.
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198 ANNUAL REPORT
SPECIFICATIONS FOR CONCRETE SIDEWALKS*
The following represents a good specification form for sidewalk
construction as prepared by the writer:
Bstimato No No. of Street.
Ordinance Page No. of Letting.
SPECIFICATIONS.
For Improving
From
To
With Sidewalk requiring
approximately square feet
Requirements^ — All sidewalks shall be feet, inches ( — ft.
in.) in width, the top of said walks when complete to be at the grade
established by the engineer, with a slope of one-fourth inch to the foot
toward the center of the street. All walks shall be laid with a space of
inches between the inner edge of the walk and the lot line, except
by special permit from the ( ).
Proper authority.
Grading* — ^AU cutting and filling necessary to bring the foundation
to subgrade, as given by the engineer, must be done by the contractor^
Wherever the soil is clay, peat or black mold, it must be removed to a
depth of ten and one-half (ioj4) inches below the finished grade and
cinders, sand or gravel filled in and thoroughly packed, rammed or rolled
solid to make a foundation six (6) inches thick. All foundations must be
brought to a subgrade four and one-quarter (4J4) inches below finished
grade and rammed solid before laying the concrete. Soft and spongy
places must be entirely removed and sand filled and rammed in the place.
Concfctc^ — On the foundation thus prepared shall be spread a layer
of concrete, which shall be three and one-half (3J^) inches in thickness,
after being thoroughly compacted. The concrete shall be composed of
one part of the best quality of Portland cement, two parts clean, coarse,
* sharp sand, and five parts of broken stones or clean, coarse gravel, of a
size not larger than will pass through a ij4 inch ring. The sand and
cement shall first be thoroughly mixed dry, then water added and the
mortar mixed, after which the stone shall be added and the whole mass
again evenly mixed until every particle of stone is completely coated
with mortar. The concrete shall be quickly placed in position and
thoroughly rammed over its whole surface with an iron shod rammer
eight inches square and weighing not less than twenty pounds.
Top Dressing* — Upon this layer of concrete, before it shall have
set, shall be spread a finishing coat three-quarter (^) inch in thickness,
composed of one part of the best Portland cement and one and one-half
parts torpedo gravel or other gravel satisfactory to the engineer: said
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S.TATE GEOLOGIST. 199
coat to be thoroughly troweled and floated smooth. In both founda-
tion and surface layers of concrete, transverse jdnts shall be cut at five
foot intervals along the walk to allow for expansion and contraction and
to more easily provide for any possible settlement or heaving. The
surface shall not be dusted with dry cement at any time. Bevel all
edges of the blocks. Sprinkle the surface two or three times each day
for a week and protect it from the hot sun during the same period.
Drainage* — ^Where the engineer may think it necessary, the con-
tractor shall lay two or four inch tile drains from the subfoundation to
the nearest catchbasin or open ditch, to carry away any water which
may collect in the subfoundation.
Qeaning Up» — ^After the walk has been completed, the contractor
shall remove all debris, waste material and excavated earth from the
street and leave the parkways in good condition.
The undersigned hereby certifies that he has read the foregoing
specifications, and that the proposal for the work is based on the condi-
tions and requirements embodied therein, and should the contract be
awarded to him, he agrees to execute the work in strict accordance
herewith.
Name
Residence
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200 ANNUAL REPORT
The following sets of specifications for concrete sidewalk are given
here for further comparison with the preceding form.
The specifications in use in Chicago, 111., are as follows:
CITY OF CHICAGO SPECIFICATIONS FOR CONCRETE SIDEWALKS.
All cutting and filling necessary to bring the fcFundation to sub-grade,
as given by the engineer in charge of the work, must be done by thei con-
tractor. When necessary the foundation must be consolidated by wetting,
rolling or ramming to give it proper stability. Soft and spongy places
not affording a firm foundation must be dug out and re-filled with sand or
grav^l, and well compacted by ramming, and foundation brorught to within
four and one-half (4%) inches of the grade.
On the surface thus prepared shall be placed a layer of hydraulic cement
concrete for four (4) inches in thickness, composed of one part best Portland
cement, two parts best clean, coarse, sharp sand. After mixing dry, five parts
of broken stone, of a size not larger than two and one-half (2^) inches In
dimensions, shall be added and then water added in Just sufficient quantity
as will give a surplus of moisture when rammed.
The second layer or finishing coat, one-half {%) inch in thickness, to be
made of one part best imported Portland cement and one part torpedo gravel
to be used before the first layer has set.
The undersigned hereby certifies that he has read the foregoing speci-
fications, and that his proposal for the work is based on the conditions and
requirements embodied therein, and should the contract be awarded to him
he agrees to execute the work in strict accordance herewith.
Name Residence
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STATE GEOLOGIST. 201
The specifications in use in Columbus, Ohio, are as follows:
SPECIFICATIONS FOR IMPROVING SIDEWALKS WITH ARTIFICIAL STONE, IN THE
CITY OF COLUMBUS, OHIO.
1. By "artificial stone" herein specified is meant a composition of Port-
land cement, sand, and fragments of natural stone.
2. By "sub-grade" is meant the ground surface upon which the pavement
foundation is laid.
3. By "sub-drainage" is meant a line of three (3) inch diameter, round,
butt-Jointed, hard-burned drain tile, laid in a trench one foot wide and one
foot deep below sub-grade, parallel to the direction of the sidewalk, and true
for line and grade, the trench to be filled to the sub-grade with broken stone,
crushed or screened gravel as herein specified for concrete, which shall be
compacted by ramming, care being used not to disturb the drain tile. The
out-let or discharge for the drain to be by connection with the street inlets,
or, in the absence of street inlets, by such other arrangement as the Engi-
neer may prescribe.
4. By "cinders" is meant clean, sharp, soft coal cinders, free from ashes
and clinkers.
5. By "screened gravel" is meant clean sharp bank gravel, free from,
loam or vegetable matter, so screened that no fragment will measure more
than inches on its longest diameter, and not enough of these
to make the quantity of fine gravel so small as to prevent its packing readily
under the roller. The question as to whether the material is too fine or too
coarse, and as to its general suitableness for the purpose for which it is
intended, shall rest entirely with the engineer.
6. By "sand" is meant clean, sharp bank sand, free from loam, vegetable
matter, or fragments of coal, and screened free from pebbles.
7. By "broken stone" is meant granite, trap-rock, hard limestone, or
other hard durable stone, so broken or crushed that no fragment will measure
more than one and one-half (1^) inches on its longest diameter, nor less
than one-half (%) inch on its shortest diameter, to be entirely free from
dust or dirt.
8. By "cement" is meant German or American Portland Cement. The
cement to be received on the work in unbroken packages, to be fresh, free
from lumps, and subject to Inspection by the Engineer In every case.
9. By "crushed gravel" is meant clean sharp bank gravel, free from
loam or vegetable matter, so broken or crushed that no fragment will
measuring more than one and one-half (1^) inches on its longest diameter.
10. By "paving" is meant the laying of an artificial stone pavement
where the sidewalk has not been previously paved with artificial stone.
11. By "repairing" is meant restoring in part artificial stone sidewalks
previously laid.
PAVING.
Sub-grade* — The sub-grade will be brought to an even compact surface
uniformly twelve (12) inches below the proposed surface of the finished
pavement. Soft or spongy earth, vegetable or other perishable matter will
be removed, and the space filled with gravel or broken stone thoroughly com-
pacted by ramming.
Sub-drainage* — Sub-drainage will De put in where the Engineer directs.
Foundation* — Upon the sub-grade thus prepared will be spread a bed of
cinders, crushed or screened gravel, in sufficient quantity to insure a uniform
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202 ANNUAL REPORT
depth of eight (8) inches after being compacted by wetting and rolUng or
ramming, the surface of the cinder, crushed or screened gravel, foundation to
be even, parallel to the proposed pavement surface and four (4) inches
below it.
Goncrete. — ^Upon the foundation will be placed a layer of concrete. This
concrete will be spread and rammed to an even surface, parallel to, and one
(1) inch below the proposed pavement surface before any set in the mor-
tar can occur; the concrete must be composed of one (1) part, by measure,
of cement, two (2) parts sand, and four (4) parts broken stone, crushed or
screened gravel. The cement and sand will be thoroughly mixed dry and
then made into mortar with the least possible amount of water. The broken
stone, drenched with water, will then be incorporated with the mortar. The
concrete will be thoroughly mixed, the mixing to continue until each frag-
ment of stone is completely coated with mortar, spread and rammed until
free mortar appears on the surface, which shall be smooth and one (1) inch
below the pavement grade. The whole operation of mixing and laying the
concrete will be performed as expeditiously as possible by a sufficient number
of skilled men. Platforms or boxes will be used in every case for the con-
crete bed.
'Wearing Surface* — The wearing surface will be composed of one (1)
part, by measure, of cement, and one (1) part sand, thoroughly mixed dry,
with the addition of sufficient clean water to form a stifC mortar. This mortar
will be evenly spread upon the concrete base before any set can occur in the
mortar and before the concrete has become dry. The mortar, as soon as
spread, will be floated and troweled to a true smooth surface at the sidewalk
grade, neatly and accurately fitted around all openings or immovable objects
in the sidewalk and along the outside margin. Boxes will be used in every
case for the mortar bed.
Blocking* — The surface of the pavement, before the mortar sets, will
be cut into blocks with a wedge-shaped tool, leaving a clean groove five-eighths
(%) of an inch dieep, one-eighth (%) of an inch wide at the bottom, and one
quarter (%) of an inch at the top, the cut to be finished with a T shaped
tool, the object of this being to make firm, smooth, and slightly round the top
edges of the groove. The blocks will be made with straight sides, gen-
erally rectangular, measuring, ordinarily, not less than four (4) nor more
than six (6) feet on a side. The design of the blocking to be subject to
special direction by the Engineer in each case. The blocking for driveways
will be done by cutting and finishing as before described, except that the
grooves will be one-fourth {y^) of an inch at the bottom and one-half of an
inch (^) at the top or pavement surface, the design to be furnished by the
Engineer, and will generally be in strips six (6) inches wide across the drive-
way (along the pavement) or in six (6) inch squares.
Grade of Sidewalk* -The full-width sidewalk, at its Junction with the
curb, will be, unless otherwise ordered by the Engineer, one-half (%) inch
above the curbing, with a neat bevel and a slight lap. The slope of the
full width pavement will be three-eighth (%) of an inch per foot, up
from the curb to the lot line, unless otherwise directed by the Engineer. The
alignment, elevation, and slope of pavements less than the full width of the
sidewalk will be subject to special direction from the Engineer in each case.
Driveways* — The construction of driveways will be with the same materials
and in the same manner as specified for "Paving" except that the gravel or
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STATE GEOLOGIST. 203
cinder foundation will be five (6) inches thick, the concrete five (5) inches
thick, and the top surface two (2 inches thick.
Repairing* — In repairing, such portions of the existing artificial pavement
as ordered by tfie Engineer shall be removed and new work substituted,