196 
ANNUAL REPORT 
regular proportioning of materials can be controlled and the product 
delivered be of the required consistency and thoroughly mixed. 
Consistency. fhe 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. 
Courses—(1) Each 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 skall 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. 
Expansion 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.—Conecrete 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. 3 
(4) The torms 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, 
ete., when not finished with natural stone coping, shall be finished 
