Concrete paving blocks with high strength and low efflorescence

Patent metadata

Field	Value
Publication number	US-2023159396-A1
Application number	US-202217984217-A
Country	US
Kind code	A1
Filing date	Nov 9, 2022
Priority date	Nov 11, 2021
Publication date	May 25, 2023
Grant date	—

Abstract

Efflorescence resistance of concrete blocks is enhanced through the use of glass powder in the concrete composition. The glass powder permits a reduction in the cement content; the glass powder also creates a pozzolanic reaction to change the free calcium ions in calcium hydroxide to calcium silicate to fix the calcium ions inside concrete. The composition includes cementitious binding material of ordinary Portland cement, fly ash, calcium sulfoaluminate cement, ground-granulated blast-furnace slag in an amount from 20 to 25 wt. %. Coarse aggregate is provided from 10 to 15 wt. percent. Fine aggregate is from 32 to 39 wt. %. The composition further includes glass powder having a diameter of less than approximately 75 microns in an amount from 17 to 23 wt. %. Water is present in an amount from 6 to 9 wt. %. The dry density of formed paving blocks is 1800-2200 kg/m3.

First claim

1 . An efflorescence-resistant concrete paving block composition comprising:
a cementitious binding material selected from one or more of ordinary Portland cement (OPC), fly ash (FA), calcium sulfoaluminate cement (CSA), ground-granulated blast-furnace slag (GGBS), metakaolin (MK), or silica fume (SF); coarse aggregate, wherein at least 90 percent of the coarse aggregate has a diameter of less than approximately 10 mm; fine aggregate having a diameter of approximately 0.75 to 4.75 mm; glass powder having a diameter of less than approximately 75 microns; water; and plasticizer; wherein a ratio of water to cementitious binder material is 0.2 to 0.5 by weight; a ratio of coarse plus fine aggregate to cementitious binder material is 2 to 6 by weight; a ratio of fine aggregates to coarse aggregates is 2 to 5 by weight; and a dry density of formed paving blocks from the composition is 1800-2200 kg/m 3 .

2 . The composition of claim 1 , wherein the fine aggregates have 40-50% of a particle size within the range of 1.18-2.36 mm and 30-40% of a particle size within the range of 0.3-0.6 mm.

3 . The composition of claim 1 , wherein the binder includes a mixture of ordinary Portland cement (OPC) and fly ash (FA).

4 . The composition of claim 1 , wherein the glass powder is recycled glass powder.

5 . The composition of claim 1 , wherein a ratio of water to cementitious binder material is 0.3 to 0.35 by weight.

6 . An efflorescence-resistant concrete paving block formed from the composition of claim 1 .

7 . An efflorescence-resistant concrete paving block composition comprising:
a cementitious binding material selected from one or more of ordinary Portland cement (OPC), fly ash, calcium sulfoaluminate cement (CSA), ground-granulated blast-furnace slag (GGBS) in an amount from 20 to 25 wt. %; coarse aggregate having a diameter less than approximately 10 mm in an amount from 10 to wt. percent; fine aggregate having a diameter of approximately 0.75 to 4.75 mm in an amount from 32 to wt. %; glass powder having a diameter of less than approximately 75 microns in an amount from 17 to 23 wt. %; water in an amount from 6 to 9 wt. %; and plasticizer; wherein the dry density of paving blocks formed from the composition is 1800-2200 kg/m 3 .

8 . The composition of claim 7 , wherein the fine aggregates have 40-50% of a particle size within the range of 1.18-2.36 mm and 30-40% of a particle size within the range of 0.3-0.6 mm.

9 . The composition of claim 7 , wherein the binder includes a mixture of ordinary Portland cement (OPC) and fly ash (FA).

10 . The composition of claim 7 , wherein the glass powder is recycled glass powder.

11 . The composition of claim 7 , wherein a ratio of water to cementitious binder material is 0.3 to 0.35 by weight.

12 . An efflorescence-resistant concrete paving block formed from the composition of claim 7 .

Assignees

• Nano & Advanced Materials Inst Ltd

Inventors

• Chen Binmeng
• Liu Xuan
• Liu Bin
• Sham Man Lung

Classifications

• Y02W30/91

  Use of waste materials as fillers for mortars or concrete · CPC title

• C04B2103/30

  Water reducers, plasticisers, air-entrainers, flow improvers · CPC title

• C04B14/06

  Quartz; Sand · CPC title

• C04B18/167

  Recycled materials, i.e. waste materials reused in the production of the same materials · CPC title

• C04B14/22

  Glass {; Devitrified glass} · CPC title