MATERIALS USED IN CONSTRUCTING CEMENT 
AND CONCRETE FENCE POSTS* 
By H. M. BAINER and H. B. BONEBRIGHT 
PART I. 
GENERAL STATEMENTS 
Cement .—In cement fence post construction, it is desirable 
that the post be made as light and as strong as possible, and thus 
it is practical to use nothing but the best grade of Portland 
cement. 
Sand. —Clean, sharp sand with grains varying in size from 
small to large makes the best mixture. Sharp sand is composed 
of sharp, angular grains of all sizes and makes a better mixture than 
that which is smooth and round, or “river-worn.” 
A sand composed of fine and coarse grains mixed, is to be 
preferred, because less cement will be required to fill the voids than 
either used by itself. 
Leaves, sticks, stones or gravel should be removed by screening. 
Gravel .— The same general rules used in the selection of a 
good grade of sand will apply to gravel. It should be composed 
of clean, sharp pebbles of all sizes. For post construction, the 
pebbles must not be too large, as they will interfere with the proper 
placement of reinforcement. 
Broken Stone .—^Broken stone used for post construction 
must contain no large pieces as they will interfere with the place¬ 
ment of the reinforcement. It is necessary to use some sand with 
the stone to fill voids and thus save cement. It is not desirable to 
use soft sandstone, soft limestone, slates, or shales. Granites, hard 
limestones, and coarse gravel, which has been crushed, is considered 
best. 
Water .—The water used in making a cement or concrete 
mixture should be clean and free from alkali or acids. 
Proportions .—On account of the difference in the total 
open space or voids in sands or gravel composed of different sized 
particles and also that more cement is required in some conditions 
than in others, it is often necessary to make a rough determination 
of the percentage of voids to the total aggregate. Where maximum 
strength is required about io per cent, more cement should be used 
than the total voids. 
The determination may be made as follows: Secure a water¬ 
tight box or pail of known capacity, fill it with the aggregate to be 
used so that when it has been well shaken it will smooth off even 
* This bulletin is an abbreviated edition of Bulletin No. 148 of June. 
1 909. A large part of the details of the tests have been omitted, but all 
the important results are summed up in the tables here presented. 
