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J. J. EARLEY.
METHOD OF PRODUCING A PREDETERMINED COLOR EFFECT IN CONCRETE AND STUCCO.
APPLICATION FILED JULY 6, 1920.
1,376,748. Patented May 3,1921,
UNITED STATES PATENT OFFICE.
JOHN J. EARLEY, OF WASHINGTON, DISTRICT OP COLUMBIA.
METHOD OF PRODUCING A PREDETERMINED COLOR EFFECT IN CONCRETE AND
Specification of Letters Patent. Patented May 3, 1921.
Application filed July 6, 1920. Serial No. 394,104.
To all whom it may concern:
Be it known that I, John J. Earlet, a citizen of the United States, and a resident of Washington, in the District of Columbia, 5 have invented certain new and useful Improvements in Methods of Producing a Predetermined Color Effect in Concrete and Stuccoj o_f which the following is a specification.
10 This invention relates to a method of treatment of structural surfaces which is broadly" known as stucco. This improved method is also applicable to the formation of concrete floors, ornamental urns, pillars,
15 arches, balustrades, building details, etc.,
and by this method, a greater variety of
color and texture schemes may be had, than
with any known process now in use.
Broadly, the object of this invention is to
20 reproduce in concrete a surface colored after the "impressionistic school."
Another object is to so control the amount of large aggregate and cementing material that the desired true color will result with
25 the minimum amount of interference of false tints.
Still another object of this invention is to obtain the desired texture on the finished product by the grading of the aggregate.
30 Still another object is to devise a method of stuccoing which will be uniform at all times. This, heretofore has been purely a matter of guess work and depending on skill alone to match the color and texture of
35 the former work.
In the figure A is a graphic illustration of concrete made after this method.
B is a graphic illustration of concrete made after the ordinary method.
40 The major difference between the appearance of stucco and concrete treated by my process and that of stucco and concrete not so treated lies in the gradation of the aggregate. Other operators and investigators
45 have studied the gradation of aggregate and the laboratories and the profession have accepted the definition of a well graded aggregate to be one in which the particles are evenly divided both as to size and number
50 running from fine to coarse. A graphic illustration is given in the accompanying diagram, of the ordinary method as graph B. An aggregate, according to this principle, is well graded or not in just such a
65 degree as the curve of its granular analysis
on this diagram 'conforms to or differs from the ideal diagonal straight line. The type of gradation is called a "straight line gradation" because its ideal finds expression in such a line on this diagram. The character- 60 istics of materials graded on this principle or any approximation of it, are not suitable to the expression of form, color and texture in the materials and for the purposes under consideration. My investigation has led to 65 the discovery that the proper gradation of aggregate for the particular use, is one in which the aggregates are divided into groups, the particles of which are all of about one size and recombined with a defi- 70 nite ratio of size of the grains and the volume of each size.
Graph A shows a diagram expressing my improved method of grading as opposed to the one mentioned above. This type of 75 grading is called "step pradation."
Stucco or concrete prepared by my process differs from the usual stucco or concrete in that it has in an artistic and an architectural sense;, better form, color and tex- 80 ture.
It has better form because under this method it can be successfully molded into more complicated shapes than the ordinary material and therefore it is better able to 85 express architectural and artistic design.
It has better color and texture because it receives its color and texture from the large aggregate, which is an element which may be carefully selected for color and carefully 90 graded to a definite size of grain for texture.
The ordinary material derives its color mainly from the cementing materials and the finest of its ingredients, and as the cement- 95 ing material is a false color, the true color of the whole will be limited by the extent of .the interference of the cementing material. Stucco or concrete prepared by my method derives its color mainly.from the 10° coarsest of its materials, the finest of which may be also carefully selected as to color, in order to reduce the interference of the cementing material to a minimum.
In ordinary material the texture-is largely 105 a function of the character of the combined materials, while in this process it is largely due to the character of the coarse material or the large aggregate. Thus, by controlling the dimensions and number of the,large HO
aggregate, the desired texture will be obtained.
The selection of large aggregate to obtain the desired color and texture is a matter of 5 personal taste and judgment and in, it is found the expression of artistic ability, which is a personality and therefore artistic, architectural and manipulative skill is necessary to obtain the maximum amount
10 of success, which is not possible without grading by the above method.
In the process herein described, great care must be exercised so that the particles of each group of aggregate will take their place
15 in the mass in1 such a way that when the surface treatment is applied they will be where they were designed to be. This part of the process is one of careful supervision and fine workmanship based upon experience
20 Avith materials having the characteristics which this step gradation gives, not otherwise possible.
Having now described the selection of the large aggregate which is the factor upon
25 which the color arid texture of the work de
pends, we now take up the two other ele
ments, namely cementing material and
Any suitable brand of Portland cement
30 may be used in a proportion which is sufficient to produce concrete of the required strength, but not so much as will' disturb the character of the aggregate by over filling the voids therebetween. If this is done,
35 both the color and texture schemes may be disturbed to such an extent as to be entirely lost. /
Water must be added of a sufficient quantity to hydrate the cement and to form a
40 mass of the proper consistency or flow to permit it to be worked, This proportion naturally varies with the character of the Avork. i'or instance, if the work is to be of a molded nature, the consistency should be at
45,tained by the addition of the least amount of water which will give to the mass of concrete a property by which it can be made to flow into the interstices of the mold which it is to fill. In the case of stucco work the
50 consistency or flow should be attained by the addition of the greatest amount of water that will not cause slip or segregation. The other two factors remain the same in both
55 It is impossible to state definitely a quan
tity of each ingredient as the proportions
vary greatly and experience is the factor
which will decide in all cases.
In the case of molded work, the mass of
60 concrete is packed carefully into any suitable mold of a waterproof construction, so that each part of the mold comes in contact
with the mass. In stucco work, the mass is applied with a trowel to any of the approved building structures such as brick, 65 stone work, metal lath, etc.
• In both of the above cases, upon hardening it will be found that a greater concentration of small aggregate and cementing material will appear at the surface of the 70 mold or the exterior of the stucco work. The larger aggregate will be found to lie in substantially a plane surface about -^" beneath the surface and may be exposed by brushing away the surface with a wire 75 brush. If desired the exposed surface of large aggregate may be treated Avith a weak acid to better bring out the natural color of the same.
When the surface is thus exposed, it will 80 be found that the groups of aggregates selected will lie in such a definite relation to each other that a pleasing and artistic surface results, having an exceptionally good architectural form, texture and color. 85
Examples of stucco and concrete work produced after this improved method can be seen in the:
Entrance to Meridian Hill Park, Washington, D. C.; 90
House front—2017 Q street, Washington, D. C.;
Field house, East Potomac Park, AVashington, D. C.;
Interior Avail, Cafe St. Marks, Washing- 95 ton, D. C.;
Cumberland Opera House, Cumberland, Maryland.
What I claim is:—
1. A method of producing a predeter- 100 mined color effect in concrete Avhich includes the steps of grading aggregate into
a definite grade of size and color, commingling said grade of aggregate Avith cementing material and Avater, molding or applying 105 the resultant mixture, and treating the surfaces of the Avork so that said aggregate protrudes from said surface.
2. A method of producing a predetermined color effect in concrete Avhich in- 110 eludes the steps of grading aggregate into definite groups of size and color, cominin- . gling said aggregates Avith cementing material and water and molding or applying the resultant mass, said groups being \vide.ly 115 separated as to size, the particles of the smaller group arranging themselves betAveen particles of the next larger group so as to reduce the visual color effect of the cementing material to a minimum and treating 120 the surface of the work so that said aggre- • gate protrudes from said surface.
In testimony whereof I affix my signature.
JOHN J. EABLEY.