Compositions and methods of utilizing recycled glass in backfill compositions
Disclosed herein are compositions and methods relating to fine aggregate for a Controlled Low-Strength Material (CLSM) recycled from a consumer waste stream of bottle glass. Such disclosed compositions may be advantageous, for example, for backfilling trenches in street cuts for utility repairs or new utility installations, such as digital cables. The disclosed compositions that incorporate the recycled glass aggregate into a CLSM that achieves satisfactory compressive strengths. The disclosed compositions are not negatively impacted by Alkali-Silica Reactivity causing expansion.
1 . A composition for a controlled low-strength materials concrete comprising:
between 60% and 95% aggregate by weight of the composition, wherein the aggregate comprises glass;
between 3% and 25% Portland cement by weight of the composition; and
between 5% and 40% water by weight of the composition;
the composition having a compressive strength of between 20 psi and 2000 psi after 7 days, and the composition having a compressive strength between 15 psi and 2000 psi after 28 days.
2 . The composition of claim 1 , wherein the aggregate is between 60% and 70% by weight.
3 . The composition of claim 1 , wherein the aggregate is substantially free of sand.
4 . The composition of claim 1 , wherein the glass is recycled glass.
5 . The composition of claim 1 , wherein the aggregate comprises greater than 5% by weight of the glass.
6 . The composition of claim 1 , wherein the glass has a particle distribution wherein greater than about 50% of the particles pass through a #16 sieve mesh.
7 . The composition of claim 1 , wherein the glass comprises a blend of at least two grades of glass, each grade of glass having a corresponding particle size distribution.
8 . The composition of claim 7 , wherein the blend comprises:
about 45% by weight of a first grade of glass, wherein the first grade has a first particle distribution wherein about 56% of particles pass through a #16 sieve mesh; and
about 55% by weight of a second grade of glass, wherein the second grade has a second particle distribution wherein about 73% of particles pass through a #30 sieve mesh.
9 . The composition of claim 7 , wherein the glass comprises a blend of three grades of glass, each grade of glass having a corresponding particle size distribution.
10 . The composition of claim 9 , wherein the blend comprises:
about 35% by weight of a first grade of glass, wherein the first grade has a first particle distribution wherein about 49% of particles pass through a #16 sieve mesh;
about 20% by weight of a second grade of glass, wherein the second grade has a second particle distribution wherein about 50% of particles pass through a #30 sieve mesh; and
about 45% by weight of a third grade of glass, wherein the third grade has a third particle distribution wherein about 55% of particles pass through a #50 sieve mesh.
11 . The composition of claim 1 , wherein the Portland cement is between 15% and 25% by weight.
12 . The composition of claim 1 , wherein the Portland cement is between 3% and 6% by weight.
13 . The composition of claim 1 , wherein the water is between 10% and 20% by weight.
14 . The composition of claim 1 , wherein the composition has a compressive strength of between 100 psi and 200 psi after 28 days.
15 . The composition of claim 1 , wherein the composition has a compressive strength of between 50 psi and 100 psi after 28 days.
16 . The composition of claim 1 , wherein the composition has a compressive strength of between 1000 psi and 2000 psi after 28 days.
17 . The composition of claim 1 further comprising fibers.
18 . The composition of claim 17 wherein the fibers are between 0.05% and 0.10% by weight in the composition.
19 . The composition of claim 17 wherein the fibers are polypropylene fibers.
20 . The composition of claim 1 further comprising a polymer.
21 . The composition of claim 20 , wherein the polymer is between 0.02% and 0.07% by weight in the composition.
22 . The composition of claim 20 , wherein the polymer is hydroxypropyl methylcellulose.
23 . The composition of claim 1 , comprising:
between 60% and 70% aggregate by weight of the composition, wherein the aggregate comprises glass;
between 15% and 25% Portland cement by weight of the composition; and
between 12% and 16% water by weight of the composition;
the composition having a compressive strength of at least 800 psi after 7 days, and the composition having a compressive strength of at least 1000 psi after 28 days.
24 . The composition of claim 1 , comprising:
between 70% and 95% aggregate by weight of the composition, wherein the aggregate comprises glass;
between 3% and 5% Portland cement by weight of the composition; and
between 5% and 20% water by weight of the composition;
the composition having a compressive strength of at least 20 psi after 7 days, and the composition having a compressive strength of at least 50 psi after 28 days.
25 . The composition of claim 24 , wherein the composition has a compressive strength of between 50 psi and 300 psi after 28 days.
26 . The composition of claim 25 , wherein the composition has a compressive strength of between 50 psi and 150 psi after 28 days.