Composite pavement for highways, streets and airports with enriched limestone quarry waste as a coarse aggregate for the concrete of the subbase

Abstract

Composite concrete pavement includes a surface course of normal concrete and a subbase or lower layer of concrete with coarse aggregate defined as enriched limestone waste of grading intermediate between coarse and fine aggregates. Coarse aggregate of this concrete is an enriched by-product of the manufacture of crushed limestone of regular sizes. As a raw material for enrichment, it should be finer than 9.5 mm. the amount of aggregate finer than 4.75 mm as a part of the total weight of aggregate should be not less than ½ before enrichment and close to, but not exceeding, ⅔ in the aggregate bin. Specified compressive strength and modulus of rupture of this concrete are up to 5,000 psi and 750 psi, respectively.

1 . A composite concrete pavement of highways, streets, and airfields comprising a surface course of thickness determined by requirements for abrasion resistance and a concrete subbase wherein the coarse aggregate of the concrete of said subbase is of small grains crushed limestone finer than 9.5 mm of grading intermediate between the least Size of coarse aggregate No.89 and largest Size No.9 of fine aggregate according to ASTM C33, the amount of material finer than 4.75 mm being about ⅔ of the total weight of said coarse aggregate.  
   
   
       2 . The composite concrete pavement of  claim 1  wherein the coarse aggregate of the concrete of said subbase is defined as enriched limestone waste and is a by-product of the manufacture of limestone coarse aggregate of regular sizes.  
   
   
       3 . The composite concrete pavement of  claim 1  wherein the concrete of said subbase is characterized by specified compressive strength fc′ and modulus of rupture up to 5,000 psi and more than 750 psi, respectively.  
   
   
       4 . The composite concrete pavement of  claim 1  wherein said surface course is of concrete with hard rock as a coarse aggregate.  
   
   
       5 . The composite concrete pavement of  claim 1  wherein said surface course is of asphalt.  
   
   
       6 . The composite concrete pavement of  claim 1  wherein the amount the of coarse aggregate of the concrete of said subbase finer than finer than 2.36 mm corresponding to the Sieve No.8 according to ASTM C33 does not exceed about 10% of the total weight of said coarse aggregate.  
   
   
       7 . The composite concrete pavement of  claim 1  wherein the amount of the coarse aggregate of the concrete of said subbase finer than finer than 1.18 mm corresponding to the Sieve No.16 according to ASTM C33 does not exceed about 7% of the total weight of said coarse aggregate.  
   
   
       8 . The composite concrete pavement of  claim 1  wherein the amount the of coarse aggregate of the concrete of said subbase finer than finer than 0.3 mm corresponding to the Sieve No.50 according to ASTM C33 does not exceed about 3% of the total weight of said coarse aggregate.  
   
   
       9 . A composite concrete pavement of highways, streets, and airfields comprising a surface course of thickness determined by requirements for abrasion resistance and a concrete subbase of specified compressive strength fc′ and modulus of rupture up to 5,000 psi and more than 750 psi, respectively, with small grains crushed limestone finer than 9.5 mm of grading intermediate between the least Size of coarse aggregate No.89 and largest Size No.9 of fine aggregate according to ASTM C33 as a coarse aggregate wherein: 
 said coarse aggregate of the concrete of said subbase defined as enriched limestone waste is a processed by-product of the manufacture of crushed limestone of regular sizes, the physical properties of this coarse aggregate are in accordance with requirements of ASTM C33;    the amount of coarse aggregate of the concrete of said subbase finer than 4.75 mm is about two-thirds of the total weight of said coarse aggregate and less than that of the largest Size of fine aggregate number 9 according to ASTM C33;    the amount of coarse aggregate of the concrete of said subbase finer than 2.36 mm corresponding to the Sieve No.8 according to ASTM C33 does not exceed about 10% of the total weight of said coarse aggregate;    the amount of coarse aggregate of the concrete of said subbase finer than 1.18 mm corresponding to the Sieve No. 16 according to ASTM C33 does not exceed about 7% of the total weight of said coarse aggregate;    the amount of coarse aggregate of the the concrete of said subbase finer than 300 μm corresponding to the Sieve No.50 according to ASTM C33 does not exceed about 3.0% of the total weight of said coarse aggregate;    the share of cement per m 3  of mix of said concrete being in the range of 175 to 500 kg; the share of water per m 3  of said concrete mix being in the range of 140 to 225 kg; the share of sand as a fine aggregate per m 3  of said concrete mix being in the range of 500 to 950 kg; the share of said coarse aggregate per m 3  of said concrete mix being in the range of 1,080 to 1,150 kg;    
   
   
       10 . The composite concrete pavement of  claim 9  wherein said surface course is concrete with crushed hard rock as a coarse aggregate, said concrete surface course being connected monolithically with the concrete of said subbase having a specified compressive strength fc′ up to 5,000 psi and modulus of rupture more than 750 psi, the coarse aggregate of said sabbase being defined as enriched limestone waste.  
   
   
       11 . The composite concrete pavement of  claim 9  wherein said surface course is an asphalt cover layer of thickness determined by requirements for abrasion resistance, the capacity of said composite pavement being determined completely by the concrete of said subbase of specified compressive strength fc′ and modulus of rupture up to 5,000 psi and more than 750 psi, respectively, with said coarse aggregate defined as enriched limestone waste.  
   
   
       12 . The composite concrete pavement of  claim 1  wherein the compressive strength of the concrete of said subbase is higher at least by 10% and than that of concrete of the same consumption of cement with crushed limestone as a coarse aggregate of grading corresponding to that of the least Size of coarse aggregate No.89 and largest Size No.9 of fine aggregate according to ASTM C33.  
   
   
       13 . The composite concrete pavement of  claim 9  wherein the compressive strength of said concrete of said subbase is substantially as high or higher than that of concrete of the same consumption of cement and twice as high consumption of admixture with coarse aggregate of crushed granite of regular sizes No. 57 and No. 67 of nominal dimensions 25.0 to4.75 mm and 19 to 4.75 mm, respectively, while the flexural strength of said concrete is higher than that for concrete of the same consumption of cement with crushed granite of regular sizes as a coarse aggregate, concrete with crushed granite of said regular sizes being considered as the standard in the world construction practice.  
   
   
       14 . The composite concrete pavement of  claim 9  wherein the mix design of the concrete of said subbase is determined by the value of modulus of rupture equal to the mean value of 28-day flexural strength of said concrete according to Portland Cement Association Engineering Bulletin EB 109P, said mean value of 28-day flexural strength of concrete being estimated as 9.42√ f cr ′ where f cr ′ is the mean value of 28-day compressive strength defined according to American building code ACI 318 as the required average 28-day compressive strength of said concrete,  
   
   
       15 . The composite concrete pavement of  claim 14  wherein the required average 28-day compressive strength of the concrete of said subbase is determined depending on the value of specified compressive strength f c ′ of said concrete according to American building code ACI 318, the modulus of rupture of said concrete being equal to the mean value of flexural strength depending also on the value of specified compressive strength f c ′ of said concrete.  
   
   
       16 . The composite concrete pavement of  claim 14  wherein mix design of said concrete of subbase determined by said value of modulus of rupture equal to the mean value of flexural strength of this concrete can be replaced by the more convenient mix design of said concrete of specified compressive strength fc′ corresponding to said value of modulus of rupture.  
   
   
       17 . The composite concrete pavement of  claim 14  wherein mix design of the concrete of said subbase of values of modulus of rupture (MR) equal to 450, 500, 550, 600, 650, 700, and 750 psi can be carried out according to the values corresponding to the 28-day values of specified compressive strength fc′ equal to 2,000, 2,500, 3,000, 3,500, 4,000, 4,500 and 5,000 psi, respectively.