Title: A Twelve-Year Record Of Concrete Mixtures
Author(s): V. L. Glover
Publication: Journal Proceedings
Appears on pages(s): 269-280
Volumetric proportioning of aggregates for concrete was discontinued by the Illinois Division of Highways at the beginning of the 1930 construction season and the mortarvoids method of design adopt- ed in its place; aggregates were proportioned by weight and a system worked out of controlling the mixtures in the field. Accurate records of proportion- ing and results obtained during ensuing decade are compared with records of volumetric proportioning of pavement concrete during 1928 and 1929. After a period of development ( 1930 and 193 I ) of the mortar-voids method it was considered by 1932 entirely practical for use in large programs of con- struction. The marked improvement of the quality of the concrete during this period is reflected by an increase in flexural strength of about 35 percent between 1929 and 1932, as shown by the average l4-day moduli of rupture of pavement concrete-far more than can be accounted for by any increase in the quality of the cements and is believed to have been accomplished without the use of additional cement. The high standards of 1932 have been maintained.