Highly activated mixtures for constructing load bearing surfaces and method of making the same

DETAILED DESCRIPTION OF THE INVENTION The present invention may be better understood by reference to the following detailed description, taken in conjunction with the figures, in which: FIG.
1 is a photomicrograph of a typical lime-fly ash mixture dispersed in a conventional manner; FIG.
2 is a lime-fly ash mixture like that in FIG.
1 after treatment in accordance with the present invention; FIG.
3 is a photomicrograph of lime, identical to that used in the mixture seen in FIGS.
1 and 2; FIG.
4 is a photomicrograph of the lime seen in FIG.
3 after treatment similar to that used to produce the mixture seen in FIG.
2; FIGS.
5 and 6 are photomicrographs of typical bituminous fly ashes showing the glassy spheres, materials entrapped within the glassy spheres, and non-glassy particles; FIGS.
7 and 8 are photomicrographs, respectively, with polarized and non-polarized light of a cured hardened lime-fly ash mixture; FIG.
9 is a graph of unreacted calcium hydroxide remaining in cured lime-fly ash mixtures after various intervals in which mixtures treated in accordance with the present invention (but without further fly ash dilution) are compared to a mixture not so treated; FIGS.
10 and 11 are graphs of compressive strength versus lime content of lime-fly ash-sand mixtures in which mixtures treated in accordance with the present invention are compared to mixtures not so treated.
It has been found that when fly ash is produced at high temperatures in coal burning steam generators, some of the silica and alumina content of the ash solidifies in situ in the form of tiny, glassy spheres, and that such fly ash in combination with lime can be processed in the presence of such tiny, glassy spheres to produce a mixture which develops compressive strength relatively quickly and which imparts similar characteristics to a further mixture with untreated fly ash.
These relatively hard glassy spheres generally comprise 40-60% of the fly ash and are 1-70 microns in diameter, depending on the origin of the fly ash