Pre-cast pervious concrete

Abstract

A pervious concrete slab is pre-cast in a reusable mold or form to define at least one keyway configured and arranged to engage with a complementary keyway of another similar pre-cast pervious concrete slab. The concrete slab is then cured in a controlled environment, transported to an installation site, and installed.

1 . A pre-cast pervious concrete slab formed in a mold through vibration and compression, the pre-cast pervious concrete slab, comprising:
 a body having opposite first and second side edges and opposite third and fourth side edges, the body being composed of a combination of aggregate particles, cementitious materials, and water, and wherein the body includes an interconnected void content of about 10% to about 30%;   a lifting feature for allowing the slab body to be lifted, the lifting feature being integrated into the slab body and extending continuously between two of the first, second, third, and fourth side edges; and   an alignment feature for aligning the slab body with another pre-cast pervious concrete slab, the alignment feature being located at one of the first, second, third, and fourth side edges.   
     
     
         2 . The pre-cast pervious concrete slab of  claim 1 , wherein the aggregate particles comprise an average particle size of about 9.5 millimeters. 
     
     
         3 . The pre-cast pervious concrete slab of  claim 1 , wherein the cementitious materials comprise a hydraulic cement. 
     
     
         4 . The pre-cast pervious concrete slab of  claim 1 , wherein the body is further composed of one or more additives selected from the group including: plasticizer; air entrainment agent; strength enhancing agent or fiber; calcium chloride; coloring agent; water reducer; and retarder. 
     
     
         5 . The pre-cast pervious concrete slab of  claim 1 , wherein the alignment feature is integral to the body and includes at least a first edge structure extending along the first edge of the body and a second edge structure extending along the second edge of the body, the first and second edge structures having cooperatively fitting profiles, each of the first and second edge structures being defined by a cross-sectional area that is less than a maximum cross-sectional area of the body. 
     
     
         6 . The pre-cast pervious concrete slab of  claim 5 , wherein the first edge structure and second edge structure each have a thickness about half the maximum thickness of the body. 
     
     
         7 . The pre-cast pervious concrete slab of  claim 6 , wherein the maximum thickness of the body is in a range of about 50 millimeters to about 406 millimeters. 
     
     
         8 . The pre-cast pervious concrete slab of  claim 1 , wherein the lifting feature includes a channel formed between the third and fourth opposite edges of the body. 
     
     
         9 . The pre-cast pervious concrete slab of  claim 8 , wherein first and second beveled edges are formed on opposite ends of the channel. 
     
     
         10 . A water filtration system, comprising:
 a plurality of pervious concrete pavers, each composed of a combination of aggregate particles, cementitious materials, and water, and including a void content of about 10% to about 30%; and   a filtration layer positioned beneath the plurality of pervious concrete pavers within the ground surface.   
     
     
         11 . The water filtration system of  claim 10 , wherein each of the plurality of pervious concrete pavers are further composed of one or more additives selected from the group including: plasticizer; air entrainment agent; strength enhancing agent or fiber; calcium chloride;
 coloring agent; water reducer; and retarder.   
     
     
         12 . The water filtration system of  claim 10 , further comprising a subgrade layer positioned beneath the filtration layer within the ground surface. 
     
     
         13 . The water filtration system of  claim 12 , further comprising at least one of: a first filter fabric positioned between the filtration layer and the subgrade layer; and a second filter fabric positioned beneath the subgrade layer and at least adjacent to portions of the filtration layer and the subgrade layer within the ground surface. 
     
     
         14 . The water filtration system of  claim 12 , further comprising:
 a perforated pipe positioned beneath the subgrade layer, wherein the perforated pipe is coupled to a first non-perforated pipe that is coupled to a liquid container positioned within the ground surface; and   a second non-perforated pipe that is coupled to the liquid container and a water disbursement mechanism at least partially positioned above the ground surface.   
     
     
         15 . The water filtration system of  claim 10 , wherein the aggregate particles comprise an average particle size of about 9.5 millimeters and the cementitious materials comprise a hydraulic cement. 
     
     
         16 . The water filtration system of  claim 10 , wherein each of the plurality of pervious pavers further include at least a first and second keyway formed along first and second opposite edges of a corresponding paver, the first keyway and second keyway each defined by a thickness that is less than a maximum paver thickness 
     
     
         17 . The water filtration system of  claim 10 , wherein each of the plurality of pervious pavers include at least one channel formed between third and fourth opposite edges of a corresponding paver, and wherein first and second beveled edges are formed on opposite ends of the at least one channel. 
     
     
         18 . A method of forming a pre-cast pervious concrete slab for a water filtration system, comprising:
 forming a mixture comprising aggregate particles, hydraulic cement, and water;   pouring the mixture into a mold to define the pervious concrete slab;   vibrating the mixture within the mold for a first predetermined time period, wherein a frequency of the vibration is in a range of about 10 Hz to about 1000 Hz;   compressing the mixture within the mold for a second predetermined time period, wherein a pressure of the compression is in a range of about 10 psi to about 1000 psi; and   releasing the pervious concrete slab from the mold following the second predetermined time period.   
     
     
         19 . The method of  claim 18 , further comprising:
 transferring the pervious concrete slab to a holding area having a controlled ambient environment following release of the pervious concrete slab from the mold;   curing the pervious concrete slab for a third predetermined time period by misting water into the controlled ambient environment; and   transferring the pervious concrete slab to an installation site of the water filtration system following release from the mold.   
     
     
         20 . The method of  claim 18 , wherein forming the mixture further comprises adding one or more materials selected from the group including: plasticizer; air entrainment agent; strength enhancing agent or fiber; calcium chloride; coloring agent; water reducer; and retarder.