US1844153A

US1844153A - Testing device

Info

Publication number: US1844153A
Application number: US309325A
Authority: US
Inventors: Walter J Giryotas
Original assignee: ROBERT W HUNT Co
Current assignee: ROBERT W HUNT Co
Priority date: 1928-09-29
Filing date: 1928-09-29
Publication date: 1932-02-09
Anticipated expiration: 1949-02-09

Description

J Feb. 9, 1932., w. .1. GIRYOTAS 1,844,153

TESTING DEVICE Filed Sept. 29, 1928 Patented Feb. 9, 1932 V v 1 453 15 UNITE. STATE-S WALTER a. GIRYOTAS, or CHICAGO, ILLINOIS, ASSIGNOR 'ro ROBERT w. HUNT ooivrranr. or CHICAGO, rumors, A CORPORATION or irsrnewni n TESTING DEVICE H V I Application filed September 29, 1928. Serial :No. 309,325;

This invention relates to the design and To determine the'fineness modulus of agcontrol of concrete mixtures and aims to progregate according to the illustrative. provide improved means for efiecting such decedure and with theuse of the apparatus i d t L shown in the drawings, the cylinder which 5 The invention may be readily understood for the finer aggregate may conveniently be 5 from the following description of one proaloouttwo inches in diameter and teninches cedure in which the apparatus illustrated in high, is filled to the top with a representative the drawings is employed in connection with Sample of the aggregate. ltshould be noted determining certain properties of aggregate that in the event the aggregate contains very ("0 f concrete coarse material, a somewhat larger cylinder co In said drawings: may advantageously be employed, The ac- Fig. 1 is an elevation, partly in section, oi! tual volume of the cylinder is immaterial a measuring device containing a quantity of S1 1 the fin ness 'llhisd pends upon the I aggregata relative percentages of diiierent sizes of ma- Fig. 2 is a similar view of the same device t rlals. "The aggregate in the cylinder is containing a different percentage of aggrethen graded and Si by fiseries of n t ardscreens or sieves, one type of which is Fig. 3 is a cross section taken along the line Illustrated my -p g app cation of Fig filed concurrently herewith Serial No. 309,326.

Concrete is a mixture of cement, water and n Order t Standardize sieves and S inert materials known as aggregate, manipu- Sizes, the fP Wl Q; sieves are emp y in lated and handled in plastic condition, but the elinlnatlonr 1 inch mesh, inch hardening soon after upon hydration of the h, 3 lnch'mesh, No. 4, No. 8; N NO- cement. Recent studies in the design of con- 3 N0. 50, No. 100. The mesh of the last six 25 crete mixtures has demonstrated that the Smiles; IB PQIlGS' With its size number.

Character f th Concrete d d upon th That 1s,l\'o. 4sieve"has feur mesh to the inch ratio of water used, upon the character of 8 elght t-O he 111611 and-so on.-

the aggregate, and of course upon the quan- The e ure of aggregate is first dumped" tity of cement used. The following descrip lh the lllch Sieve h I 1111ar1ly none so fion deals with determining th ti t w1ll remain on the sieve slnce-in practice the so characteristics of the aggregate employed. gg g does not Contain m r Wh h Aggregate is generally classified into fine W n 'p s h ugh a 1 inch mesh. It is and'coarse materials, the fine usually consistth up -p p n he inch meshsieve ing of sand and fine gravel and the cgarse of and the residue remaining 011 the SiEVE', that coarse gravel or crushed stone, etc. In order is e gg ga which W not p s h g 35 to determine the most economical proportions the inch mesh, is returned to the cylinder of t. d r at fo od ing @011. .10. The percentage of this residue to the tocrete of the desired strength and other chartal is determined by the graduated measuracteristics, it is necessary to know the fineg p g 11 wh in this instance is in ness modulus of the aggregate. The fineness the form ofja closed cylinder of a diameter 9o modulus of the aggregate depends upon the Just small enough to slide freely within the varying proportions of the difierent sizes of cylinder 10 andcontaining a scale 12 gradumaterials comprising the aggregate. Tests atedin this instance intohundredthsthroughhave shown that aggregates having the same out a distance corresponding to the height 45 fineness modulus require equal amounts of f cylinder 10K The plunger is advantagemixing water for a given plasticity and conously provided with a handle 18. The plungsequently will produce concrete of the same er is droppe 1 0 the aforementioned strength, so long as other conditions are equal residue, leveling it in the action and indicatand the aggregate is not too coarse for the ing on the scale (see'Fig. 1) the'proportion quantity of cement used. which this residue bears to the total. Forflee example, in Fig. 1 the scale, which is zero at the top, shows that the aggregate in the cylinder is slightly more than 10% of the total volume. The percentage of this residue is then recorded and the aggregate which passed through the inch screen is then placed on the inch mesh screen and a similar operation performed for the residue which remains on the inch screen. The percentage of this residue as determined by the measuring cylinder is recorded and the procedure followed through for No. 4 screen. Quite arbitrarily all material which will not pass through a No. 4; screen is regarded as coarse aggregate and all which is finer than a No. 4 screen is regarded as fine aggregate. The sum of the percentages of the respective residues retained on the 1 inch, inch, 7 inch and No. 4 screen divided by one hundred, is the finenessmodulus for the coarse aggregate. While it is apparent that the fineness modulus depends upon the screen sizes used, such screen sizes having been standardized for this purpose, the fineness modulus then becomes an index of the characteristics of the aggregate;

with the top edge of said receptacle indicates the percentage of total cylinder volume rep resented by the space between the plunger bottom and cylinder bottom.

In testimony whereof, I have signed my name to this specification. I I r i WALTER J. GIRYOTAS,

A similar procedure is followed through vided by one hundred representing the fineness modulus of the fine aggregate. The total of the two fineness moduli is the fineness modulus of the aggregate as a whole.

The fineness modulus thus determined, as stated above, is anindex by means of which can be determined the proper volume of aggregate which should be used in a givenconcrete mixture.

In order to obtain mixed aggregate having a given fineness modulus, the respective moduli of the fine and coarse aggregate as above determined, may be utilized in an obvious manner to determine the necessary proportions of fine aggregate and coarse aggregate to the total aggregate.

Obviously the invention is not limited to V the precise details of the illustrative embodiments thereof herein described, since such details may be variously modified. Moreover, it is not indispensable that all features be used conjointly since various features may be advantageously used in different combinations and sub-combinations.

Having described one embodiment of my invention, I claim:

A device for use in determining the fineness modulus of aggregate for concrete comprising in combination a cylindrical receptacle closed at its bottom and open to its full cross section at its top and of uniform