SMITH R.F.O. 
Some Answers to 
Questions That 
Frequently Arise Regarding 
Concrete Work 
I want to build a concrete foundation 
for a barn, but as I won’t be able to 
place the concrete all at one time, please 
advise how I can do the work from day 
to day and get the best results. 
It rarely happens that all the concrete can 
be placed at one time unless it is a very small 
job. When you have done about as much 
work as you can do in a day on your founda¬ 
tion. put some clean jagged rocks in the top 
of the concrete, say a foot apart, with about 
half the rock protruding from the concrete. 
When ready to place moi'e concrete, wet the 
top surface of the hardened concrete. The 
rocks will help to make a good bond with 
the new concrete. Of course, it is necessary 
to see that the old concrete is free from all 
dirt before the fresh concrete is deposited. 
Has the aging of cement any effect 
on its strength, and can cement be stored 
for any considerable period without in¬ 
terfering with its quality? 
The aging of Portland Cement has no de¬ 
teriorating effect upon the strength, provided 
no hydration of the particles occurs. Since 
hydration can come only through the intro¬ 
duction of moisture, the solution of the prob¬ 
lem lies in keeping the cement in a dry ware¬ 
house, away from dampness. 
Sometimes when cement is stored in high 
piles for a considerable period, the cement 
in the bottom sacks becomes compacted and 
take on what is known as “storage caking,” 
which is some times mistaken for caking due 
to moisture. The cement can be shaken up 
easily, however, when the sacks are re¬ 
handled. Its strength is in no way impaired. 
Is there a simple rule for determining 
the amount of cement required by a cer¬ 
tain proportion? 
The following rule is one used by some con¬ 
tractors in getting a quick, general estimate 
of the cement required : Divide the total of 
the figures representing the proportions into 
11 and use the result as the number of bar¬ 
rels of cement needed for a cubic yard of 
cohcrete. To illustrate: The proportions 
are 1 of cement; 3 of sand; 6 of stone; the 
total of 10 divided into 11 gives 1 1-10 as the 
number of barrels of cement required for 
each cubic yard of the volume to be filled. 
This rule gives approximately correct results. 
Where gravel must be hauled, and 
good sand is on the ground, does it not 
pay to use cement and sand exclusively? 
I must pay for the hauling. How does a 
sand and cement mixture compare with 
a mixture of cement and graded gravel 
in strength? 
It will require much more Portland Cement 
to make concrete of just sand and cement 
than it will if stone, sand and cement are 
used; and stone adds sti-ength that sand 
cannot supply. Strictly speaking, the result 
r.s not concrete unless some material coarser 
than ordinary sand is used. Concrete, as the 
word IS ordinarily understood, refers to some 
kind of coarse aggregate such as pebbles, 
crushed stone, cinder, hard slag, etc., knit 
t(^ether by a mortar of sand and cement. The 
otiice of the sand and cement is to fill the 
voids in the coarser material and to knit the 
entire mass together in an everlasting bond. 
Cement is the most expensive material used 
in making concrete, and good sand, when the 
job IS a large one, represents considerable 
money. Therefore, to eliminate the coarser 
material will not only mean weaker concrete 
but ordinarily will greatly increase the cost. 
Even if hauling expense has to be incurred, 
we recommend using a mixture of one part 
cement, three parts of coarse, clean sand, 
and five parts of clean pebbles, or crushed 
stone, rather than a mixture of one part 
cement to four of sand, which is as lean a 
mixture of sand and cement as would be 
advisable. 
Often, when I am trying to get a 
smooth wall, I find that pockets have 
been left in the concrete, and this makes 
the surface look unsightly when the 
forms are taken away. How can this be 
remedied? 
The best time to remedy this fault is while 
the concrete is being placed. In the first 
place, the mixture should be mushy enough 
to pack down solidly and care should be taken 
to see that the larger stone used in the work 
is mixed well with the smaller. But even 
when this is done, it is best at frequent 
stages of the work to work a spade or other 
flat tool, dowm between the fresh concrete 
and the otiter form. This will shove the 
larger stone away from the extreme edge and 
permit the fine material to work outward. It 
f>;rthermore aids in making your concrete 
t'.iOre dense, which is very important where 
the wall is expected to re)>el water. 
What is the best way of preventing 
cracks in concrete pavements, feeding 
floors and driveways? 
Probably ninety per cent, of all cracks 
in pavements and drivew'ays are caused by 
the action of frost. The remedy is a deep, 
well laid and w ell drained subbase composed 
of material such as cinders or ashes that 
will not expand in freezing. 
Cracks come frequently from the neglect to 
provide for expansion and contraction. Con¬ 
crete that is exposed to heat and cold is sub¬ 
ject to a certain amount of contraction and 
expansion. The expansion joint should not 
be a mere ornamental line on the surface but 
should extend down through the slab. Some 
contractors provide for this by tir.st laying 
only every other slab. When the first slab.s 
are hard, the empty spaces are filled. 
I intend to put a concrete floor in a 
small power house in which will be in¬ 
stalled a gasoline engine that will be used 
for pumping, running cream separator. 
etc. How can I provide for bolting the 
engine down firmly? 
There are two ways of doing this: One i.s 
to anchor pieces of hard wood, say 4”x4” 
timber, in your concrete. The timber can be 
set flush with the floor and countersunk for a 
nut and washer. 
The other method, would be to set the 
anchor bolts in the concrete permanently. 
This can be done by making a wooden tem¬ 
plate of the base of the engine (a frame that 
will accurately locate all bolts and suspend 
them in position) ; place thi.s template in 
. position desired and fix the anchor bolts tn 
the template at a proper distance above the 
floor. 
If the concrete floor is already laid and you 
desire to anchor a gasoline engine to it, holes 
can be drilled in the concrete and anchor 
bolts securely fastened by lead, melted sul¬ 
phur or a rich cement grout. These holes can 
be drilled with an ordinary hand drill such as 
is used for drilling rock. Be sure the holes 
are drilled deep enough. 
For general purposes, how wet should 
a concrete mixture be? 
While varying quantities of w'ater are de¬ 
sirable for different types of concrete work, 
the best mixture for general purposes is one 
that “quakes” like jelly. Such a mixture 
will slowly flatten out on a board or a shovel 
but is not wet enough for the cement and 
sand—which form the binder—to separate 
from the coarse material. As thorough mix¬ 
ing is an important part of concrete work, it 
follows that it is important to prevent 
“unmiiing,” that is, letting the fine material 
run away from the coarse. 
What are the essentials of a good 
sand for use in making concrete? 
In a good sand for concrete the coarse 
grains should predominate. If some of the 
grains are % inch through, so much the 
better. Concrete made of sand that is all 
fine will likely “dust off.” There should be 
no loam, dust or vegetable matter in the 
sand. Dirty sand can be spread out on 
boards and washed, thus making it fit for use. 
From what does Portland Cement 
take the name “Portland”? 
“Portland” does not denote the place of 
manufacture. An Englishman first made 
I’ortland Cement, and he thought that the 
concrete which he made with this cement re¬ 
sembled the limestone quarried on the island 
of I’ortland. off the coast of England. Hence 
the name Portland Cement. While made ac¬ 
cording to a standard specification, Portland 
Cement is now produced by hundreds of dif¬ 
ferent manufacturers and from various raw 
materials. 
The be.st grade of Portland Cement, mixed 
pure, gives a tensile strength on “standard 
testa” of from 600 to 800 pounds in 28 days, 
W’hile natural cement reaches only about 
225 pounds. Portland Cement has several 
times the tensile strength of any mortar or 
binding material known prior to its discovery. 
If these, or any other concrete-construction (luestions or subjec-ts interest you, and you live 
east of the Mis-sissippi. tell ns what yon are i)lanning to build and we will send you a free copy 
of “ALPHA CEMENT—How' to Use It.” This is a 96-page illustrated hand-book that tells some¬ 
thing about Alpha, the hourly tested and guarauteetl Portland Cement and that shows how to 
build scores of concrete improvements. Special information will be furnished free, on request, on 
the following subjects. Check, or name, the one that interests you. 
—Walkway 
— Driveway 
— Small Bridge 
— Culvert 
— Foundation 
— Barn 
— Water Trough 
— Gutter and Curb 
•—Silo 
—Poultry House 
—Corn Crib 
—Storage Cellar 
—Small Dam 
—Greenhouse 
-Hot Bed 
•—Hog House 
— Steps 
— Porch Floor 
--Cellar Floor 
— Stable Floor 
— Feeding Floor 
— Smoke House 
—Milk House 
— Ice House 
— Spriug House 
— Manure Pit 
— Septic Tank 
— Dipping Vat 
— Tank.s 
— Tennis Court 
— Concrete Roof 
—Gate Posts 
—Walls 
—Sills 
—Lintels 
—Garages 
Piers for Small Boats —Co d-Weatht r 
Garden Furniture ^ oncrete M ork 
Fence Posts —Concrete Roads 
Address: ALPHA PORTLAND CEMENT COMPANY, Dept. R., EASTON. PA. 
or the nearest ALPHA CEMENT dealer. (We will tell you who he is, if you don't know.) 
