PERVIOUS CONCRETE LOADING, TESTING SYSTEM AND METHOD

Abstract

The invention provides a system to gauge the performance of a pervious concrete slab (1) sample in terms of mass change and permeability change, under loading conditions similar to the actual pedestrian or vehicular traffic loadings. The invention consists of a testing chamber (17) held in position by supporting members (3), which contains the pervious concrete slab (1) to be tested for change in the mass and permeability. The water head (20) is measured or maintained with the help of water chamber (19), connected to the testing chamber (17) through connecting pipe (21). The initial and permeability of the pervious concrete slab (1) is measured applying falling head test and using darcy’s law. The change in permeability of pervious concrete slab (1) also helps in gauging the pervious concrete performance in loading patterns similar to pedestrian traffic.

Specification

Description:The present invention relates to a pervious concrete loading, testing system and method. The invention provides a system to gauge the performance of a pervious concrete slab sample in terms of mass change and permeability change, under loading conditions similar to the actual pedestrian or vehicular traffic loadings.
BACKGROUND
[001] The use of pervious concrete in pavements has become popular as a way to address drainage and waterlogging issues. Due to the porous nature of pervious concrete, water can readily flow through its network of holes and into subgrade sewers or other drainage systems. In urban settings, pedestrian walkways are a good fit for pervious concrete. The loads caused by constant pedestrian movement on the pervious concrete pavement, however, cannot be accurately replicated by any equipment.
[002] The pavement experiences abrasion and recurrent impact stresses due to the constant flow of pedestrian activity. In order to measure the impact of repeated abrasive and impact loads that cause scouring, disintegration, and clogging in the pervious concrete slab sample, this invention offers a testing assembly.
[003] One such prior art US11680884B2 details about a device and a procedure for evaluating concrete's water absorption in a direction parallel to the direction of load application. A loading device, a water filling device, and a monitoring device are all part of the apparatus. The loading apparatus consists of two support plates: one higher and one lower. The two plates are joined by several threaded rods, and there is a gap between the two plates for the placement of a concrete specimen. One side of the water filling device is connected to a water supply tank through an input pipe, while the other side is connected to a water storage tank by an outlet pipe. A mass sensor is part of the monitoring apparatus and is placed beneath the water storage tank.
[004] Further, another prior art CN113984527A discloses an automatic salivation facilitating apparatus is provided, which consists of several parts: a salivation agent injection unit that is attached to the lower part of one of the first and second parotid gland massaging devices to periodically automatically inject salivation agent; a first fixing member that connects the first and second parotid gland massaging devices and allows the user to wear the automatic salivation facilitating apparatus; and a controller that operates a main body. To optimize the effect of salivation facilitation, the automatic salivation facilitating apparatus makes use of a parotid gland massaging device, a salivation agent injection unit, and a submandibular gland massaging device.
[005] Another prior art IN202111013557 discloses a four-point sealing apparatus for testing pervious concrete, designed to prevent lateral seepage and loss of water head. The device uses a metal jacket with rubber linings and lever keys for a watertight fit. However, it does not address the impact of different loading conditions or repetitive cycles on pervious concrete's performance.
[006] At present, one prior art "Pervious Concrete Testing Methods", Liv M. Haselbach et al. discloses a review of research approaches being investigated, the prior art examines some of the testing techniques for pervious concrete that are currently being developed.
[007] Another prior art "Construction of Pervious Concrete Pavement Stretch, Ahmedabad, India - Case Study", Tejas Joshi et. al. discloses a 3 m × 10 m pervious concrete pavement (PCP) was built on the campus of Nirma University in Ahmedabad, India. Evaluations were conducted on the pervious concrete's characteristics, construction process, and materials. The investigation's effective drainage performance suggested that construction might take place in India's flooded regions.
[008] The prior art discussed focuses on various methods and apparatuses developed to test and prepare pervious concrete, mainly targeting its permeability and percolation properties, but largely lacking in addressing the material's performance under different loading conditions or repeated cycles of wear and tear.
[009] There is thus a need for a system and method to revolutionize the conventional approach. While the literatures provide valuable advancements in understanding the properties and performance of pervious concrete-especially regarding permeability, pore structure, and sample preparation-there is a notable gap in addressing the material's response to different loading conditions, repeated cycles, and abrasion resistance as shall be applied by the pedestrian traffic during the service life of pervious concrete slab.
SUMMARY
[0010] Embodiments in accordance with the present invention provide a system employs a testing assembly for measuring the effect of repetitive abrasive and impact loads, causing scouring, disintegration and clogging in the pervious concrete slab sample. The effect of this loading is indicated by weight loss and change in permeability of the pervious concrete sample. The pervious concrete sample are kept in a testing chamber and the step loading is applied by metallic feet, connected to a crankshaft through connecting rods. The rotation of crankshafts cause loading on the pervious concrete slab which would imitate the actual conditions of pedestrian or vehicular traffic, to which the pervious concrete is subjected during its service life.
[0011] Embodiments in accordance with the present invention further provide the effect of varying the amount of load, number of load repetitions and the hydraulic head above the sample can also be assessed on the pervious concrete sample. The amount of load represents the weight delivered by the pedestrian on the slab. The number of load repetitions represent the service life of the slab i.e. the number of load cycles that the slab can take before failure. The hydraulic head represent the effect of the free standing water above the pavement, under flooding and intense waterlogging situations.
[0012] Embodiments of the present invention may provide a number of advantages depending on its particular configuration. Embodiments of the present application provide a system and a method. The invention is capable of gauging the effect of all realistic situations, that the pervious concrete pavement may be subjected to. This effect is gauged in terms of mass loss of the slab and loss in permeability due to clogging caused by disintegrated fragments of the pavement under the influence of repetitive loading. The invention further helps in understanding the fatigue behavior of the slab under different load or stress ratios. Conclusively, this invention provides a comprehensive testing system and method for assessment of the performance of pervious concrete pavement sample, under the loading conditions similar to the actual loadings applied pedestrian traffic. The present invention standardizes the testing method for pervious concrete slab samples and help in improvement of mix designs, assessment of using novel composite materials in pervious concrete pavements, and evolution of other novel technologies in pervious concrete.
[0013] These and other advantages will be apparent from the present application of the embodiments described herein.
[0014] The preceding is a simplified summary to provide an understanding of some embodiments of the present invention. This summary is neither an extensive nor exhaustive overview of the present invention and its various embodiments. The summary presents selected concepts of the embodiments of the present invention in a simplified form as an introduction to the more detailed description presented below. As will be appreciated, other embodiments of the present invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and still further features and advantages of embodiments of the present invention will become apparent upon consideration of the following detailed description of embodiments thereof, especially when taken in conjunction with the accompanying drawings, and wherein:
[0016] FIG. 1A illustrates a diagram depicting isometric view of the invention, according to an embodiment of the present invention;
[0017] FIG. 1B illustrates a diagram depicting top view of the invention, according to an embodiment of the present invention.
[0018] FIG. 1C illustrates a diagram depicting front view of the invention, according to an embodiment of the present invention.
[0019] FIG. 1D illustrates a diagram depicting side view of the invention, according to an embodiment of the present invention.
[0020] The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words "include", "including", and "includes" mean including but not limited to. To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures. Optional portions of the figures may be illustrated using dashed or dotted lines, unless the context of usage indicates otherwise.
DETAILED DESCRIPTION
[0021] The following description includes the preferred best mode of one embodiment of the present invention. It will be clear from this description of the invention that the invention is not limited to these illustrated embodiments but that the invention also includes a variety of modifications and embodiments thereto. Therefore, the present description should be seen as illustrative and not limiting. While the invention is susceptible to various modifications and alternative constructions, it should be understood, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.
[0022] In any embodiment described herein, the open-ended terms "comprising," "comprises," and the like (which are synonymous with "including," "having" and "characterized by") may be replaced by the respective partially closed phrases "consisting essentially of," consists essentially of," and the like or the respective closed phrases "consisting of," "consists of, the like.
[0023] As used herein, the singular forms "a", "an", and "the" designate both the singular and the plural, unless expressly stated to designate the singular only.
[0024] FIG. 1A in conjunction with Fig. 1B, 1C, 1D represents pervious concrete loading, testing system and method (hereinafter referred to as the pervious concrete loading, testing system and method 100), according to an embodiment of the present invention.
[0025] Embodiments of the present invention discloses the machine 100 comprises various elements or components. The different elements or components of the machine with their corresponding labels is represented in Table 1.
Label no. Name of component Role
1 Pervious concrete slab The pervious concrete specimen to be tested
2 Perforated steel mesh To support pervious concrete slab and allow water drainage
3 Supports of the frame To hold the testing chamber in position
4 Filter tray To retain the disintegrated fragments of pervious concrete
5 Bottom tray To collect the water drained through the pervious concrete and filter tray
6 Firm base/platform To hold the entire assembly in position
7 Guide sleeves To restrict the horizontal movement of loading assembly
8 Loading frame Frame of the loading assembly
9 & 10 Crankshafts To undergo rotation for repetitive loading
11 Gears To mutually opposite rotation in crankshafts 9 and 10
12 Axes of crankshafts Indicating axes of rotation of the crankshafts
13 Crankpins To cause oscillatory motion in connecting rods and metallic feet
14 Weight frame To support additional weights on the loading frame
15 Weights To vary the weight on the loading frame
16 Connecting rods To transfer crankpin motion to the metallic feet
17 Testing chamber To hold pervious concrete specimen and water above it
18 Metallic feet To apply repetitive loading on pervious concrete specimen
19 Water chamber To manage and gauge the water head above the pervious concrete specimen
20 Water level Indicates water head above the pervious concrete specimen
21 Connecting pipe To connect the water chamber and testing chamber
22 Supports of water chamber To hold the water chamber in position
23 Guide rods To guide the motion of connecting rods and metallic feet
24 Motor To induce rotatory motion in crankshafts and produce repetitive loading
[0026] Present invention relates to a pervious concrete loading, testing system and method. The invention provides a system to gauge the performance of a pervious concrete slab (1) sample in terms of mass change and permeability change, under loading conditions similar to the actual pedestrian or vehicular traffic loadings.
[0027] In the embodiment of the present invention, the machine comprises a testing chamber (17) held in position by supporting members (3), which contains the pervious concrete slab (1) to be tested for change in the mass and permeability. The water head (20) is measured or maintained with the help of water chamber (19), connected to the testing chamber (17) through connecting pipe (21).
[0028] According to an embodiment of the present invention, the loading assembly comprises loading frame (8), weight frame (14), weights (15), crankshafts (9 and 10), motor (24), gears (11), connecting rods (16) and metallic feet (18) rests on the pervious concrete slab (1) under the influence of self weight. The horizontal motion of loading assembly is restrained by guide sleeves (7). The rotation of motor (24) causes the crankshafts (9 and 10) to rotate in mutually opposite directions and cause repetitive loading by means of connecting rods (16) and metallic feet (18) connected to it. The fragments of disintegrated pervious concrete slab surface is retained by the filter tray (4). The mass of these fragments denote mass change of the pervious concrete slab (1). The initial and permeability of the pervious concrete slab (1) is measured applying falling head test and using darcy's law. The change in permeability of pervious concrete slab (1) also helps in gauging the pervious concrete performance in loading patterns similar to pedestrian traffic as shown in figure 1A.
[0029] In a preferred embodiment of the present invention, 12 represents the central axis of rotation of crank shafts 9 and 10 driven by motor 24 through control gear wheels 11.
[0030] In a preferred embodiment of the present invention, 22 represents the support frame for the water chamber 19 connected to the base platform 6. The supports 22 are configured to hold the water chamber in position.
[0031] FIG. 1B illustrates a diagram depicting top view of the pervious concrete loading, testing system, according to an embodiment of the present invention. The pervious concrete sample's weight loss and altered permeability serve as indicators of the loading's impact. The pervious concrete sample are stored in a testing chamber, and metallic feet (17) that are attached to a crankshaft (9 and 10) by connecting rods (16) apply the step loading.
[0032] In an embodiment of the present invention, the pervious concrete slab can experience loading from crankshaft rotation, simulating the real-world traffic situations that the pervious concrete encounter over its service life. In addition, the pervious concrete sample are evaluated for the impact of changing the load amount, number of load repetitions, and hydraulic head above the sample. The weight imparted by the pedestrian on the slab is represented by the load amount.
[0033] The amount of load repetitions indicates the slab's service life, or how many load cycles it can withstand before failing. The impact of free-standing water above the pavement in cases of flooding and severe waterlogging is represented by the hydraulic head.
[0034] FIG. 1C illustrates a diagram depicting front view of the pervious concrete loading, testing system, according to an embodiment of the present invention. In an embodiment of the present invention, the machine comprises an assembly for testing a pervious concrete slab (1) placed inside a testing chamber (17), which is firmly held in position by supporting members (3) springing from a firm base platform (6), thus constituting a frame. The pervious concrete slab (1) to be tested, rests over a perforated steel mesh (2) to allow the free draining of water. The horizontal dimensions of the pervious concrete slab (1) are same as the inner clear dimensions of the testing chamber (17), thus leaving no gaps at edges. A filter tray (4) is placed below the perforated steel mesh (2), with a purpose to collect the fragments of pervious concrete that have disintegrated under the influence of the loading and flown with the draining water. The water passing through the filter tray (4) is collected in the bottom tray (5).
[0035] According to an embodiment of the present invention, in order to apply a loading which imitates consistent pedestrian load on the pervious concrete slab (1), the motor (24) rotates the two crank shafts (9 and 10) fitted to the loading frame (8). The motor (24) is fixed in position with respect to the loading frame (8), to resist reactions of the rotation in the crankshafts (9 and 10). One of the crankshafts is (9) connected directly to the motor (24) and the other one (10) is rotated in opposite direction by means of gears (11). The crankpins (13) of the crankshafts (9 and 10) are attached with connecting rods (16) which can undergo rotation about the respective axis (12) of the crank pin, parallel to axis of rotation of the motor (24). Each of the connecting rods (16) is further connected with a metallic foot (18) at its bottom which directly transfers load to the pervious concrete pavement (1). The oscillating motion of the connecting rods (16) and the metallic feet (18) is guided by the guide rods (23) to avoid any entanglement.
[0036] According to an embodiment of the present invention, the whole loading assembly (100) consists of loading frame (8), weight frame (14), weights (15), crankshafts (9 and 10), motor (24), gears (11), connecting rods (16) and metallic feet (18). The weights (15) on the weight frame (14) can be increased or decreased by depending upon the requirement of the test.
[0037] In a preferred embodiment of the present invention, the loading assembly (100) as a whole, is free to move vertically under the influence of its gravity but restrained to move laterally (horizontally in any direction) by means of guide sleeves (7) at corners. The weight of the whole loading assembly is transferred to the pervious concrete slab (1) through metallic feet (18). This is done to ensure that the load transferred by the loading assembly to the pervious concrete slab (1) remains constant throughout the testing period. Had the loading assembly been fixed in a position vertically (i.e. not allowed to move vertically), the upper surface of pervious concrete slab (1) would be abraded in first few cycles of the test and no load would be transferred by the metallic feet (18) to the pervious concrete slab (1) in the subsequent rotation cycles of the test.
[0038] According to an embodiment of the present invention, each of the crank shafts (9 and 10) consists of multiple crankpins arranged at varying angles about its axis such that at least some of the metallic feet (18) always touch the pervious concrete slab (1) throughout the rotation cycle. This is done to avoid the loading assembly from getting stuck during the rotation cycle.
[0039] According to an embodiment of the present invention, the loading test can be performed at different water heads (20), that can be maintained with the help of water chamber (19) connected to the testing chamber by means of a connecting pipe (21).
[0040] According to an embodiment of the present invention, the permeability of the pervious concrete slab (1) under scrutiny, can be measured at any point during the test by applying the Darcy's law and performing falling head permeability test on the slab.
[0041] FIG. 1D illustrates a diagram depicting side view of the pervious concrete loading, testing system, according to an embodiment of the present invention.
[0042] According to an embodiment of the present invention, the working of the invention discloses at first, the pervious concrete slab (1) sample to be tested, is firmly placed in the testing chamber (17), over the perforated steel mesh (2). The permeability of the pervious concrete slab (1) is measured by introducing a water head (20), noting the time taken by the water to fully drain through the pervious concrete slab (1) and applying the darcy's law as shown in well accepted equation "a". After that, the loading assembly is slowly released above the pervious concrete slab (1). The weights (15) on the weight frame (14) are adjusted as per the desired loading condition. Henceforth, the desired water head (20) is introduced and maintained on the pervious concrete slab (1) by consistently adding water to the water chamber (19). The rotation of the motor (24) is then initiated which starts rotating the crankshafts (9 and 10) in mutually opposite directions. This mutually opposite motion is introduced so that any horizontal thrust exerted by the metallic feet (18) on the pervious concrete slab (1) is balanced, thus avoiding the possibility of stress concentration between the pervious concrete slab (1) and walls of the testing chamber. The rotation of the motor is continued for desired number of load repetitions as per the requirements of the test. After the desired number of load repetitions are achieved, the motor (24) is stopped, and all the water (20) is allowed to drain. The mass of the fragmentations retained on the filter tray (4) is measured, which denotes the degree of deterioration and the change in mass of pervious concrete slab (1).
[0043] According to an embodiment of the present invention, the permeability of the pervious concrete slab (1) is measured again using the falling head test, applying Darcy's law. The change in permeability also helps in deriving inferences about the disintegration, clogging and internal changes in the pervious concrete slab (1). Thus, the mass change and change in permeability on the pervious concrete sample due to a loading pattern similar to pedestrian or vehicular traffic can be found using this single invention.
(a)
k = Permeability of the pervious concrete slab (1),
a = Sum of horizontal areas of cross section of testing chamber (17) and water chamber (19),
L = Vertical depth of the pervious concrete slab (1),
A = Area of cross section of the pervious concrete slab,
t = Time taken by the water head to drop from h1 to h2,
h1 = Initial static head of water above the base of pervious concrete slab (1) and
h2 = Final static head of water above the base of pervious concrete slab (1).

[0044] According to an embodiment of the present invention, the experimental results disclose that the invention is a conceptualised system and method for testing pervious concrete slab samples. No physical prototype of the invention has been built.
[0045] According to an embodiment of the present invention, the variables available for the experiment are the permeability of the pervious concrete slab (1) is measured using the falling head test, applying popular Darcy's law representing flow of water through a permeable mass, mentioned as follows in equation (a).
(a)
k= permeability of the pervious concrete slab (1),
a=sum of horizontal areas of cross section of testing chamber (17) and water chamber (19),
L=vertical depth of the pervious concrete slab (1),
A=Area of cross section of the pervious concrete slab,
t= time taken by the water head to drop from h1 to h2 ,
h1 = Initial static head of water above the base of pervious concrete slab (1) and
h2= Final static head of water above the base of pervious concrete slab (1).
[0046] Embodiments of the invention are described above with reference to block diagrams and schematic illustrations of methods and systems according to embodiments of the invention. It will be understood that each block of the diagrams and combinations of blocks in the diagrams can be implemented by computer program instructions. These computer program instructions may be loaded onto one or more general-purpose computers, special purpose computers, or other programmable data processing apparatus to produce machines, such that the instructions which execute on the computers or other programmable data processing apparatus create means for implementing the functions specified in the block or blocks. Such computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means that implement the function specified in the block or blocks.
[0047] While the invention has been described in connection with what is presently considered to be the most practical and various embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
[0048] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined in the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements within substantial differences from the literal languages of the claims.
, Claims:1. A pervious concrete loading, testing system and method (100), the system and method (100) comprising:
a pervious concrete slab (1) placed inside a testing chamber (17), which is firmly held in position by supporting members (3) springing from a firm base platform (6), thus constituting a frame.
a filter tray (4) placed below the perforated steel mesh (2), wherein the filter tray (4) collects the fragments of pervious concrete that have disintegrated under the influence of the loading and flown with the draining water;
a motor (24) fixed in position with respect to the loading frame (8), to resist reactions of the rotation in the crankshafts (9 and 10).
a first crankshaft (9) connected directly to the motor (24) and a second crankshaft (10) is rotated in opposite direction by means of gears (11);
a plurality of crankpins (13) of the crankshafts (9 and 10) are attached with connecting rods (16) which undergo rotation about the respective axis (12) of the crank pin, parallel to axis of rotation of the motor (24); and
a water head (20) is measured or maintained with the help of water chamber (19), connected to the testing chamber (17) through connecting pipe (21);
wherein the water passing through the filter tray (4) is collected in the bottom tray (5);
wherein, each of the connecting rods (16) is further connected with a metallic foot (18) at its bottom which directly transfers load to the pervious concrete pavement (1); and
wherein, the pervious concrete slab (1) to be tested, rests over a perforated steel mesh (2) to allow the free draining of water.
2. The system and method (100) as claimed in claim 1, wherein the horizontal dimensions of the pervious concrete slab (1) are same as the inner clear dimensions of the testing chamber (17), thus leaving no gaps at edges.
3. The system and method as claimed in claim 1, wherein the oscillating motion of the connecting rods (16) and the metallic feet (18) is guided by the guide rods (23) to avoid any entanglement.
4. The system and method (100) as claimed in claim 1, wherein each of the connecting rods (16) is further connected with a metallic foot (18) at its bottom which directly transfers load to the pervious concrete pavement (1).
5. The system and method (100) as claimed in claim 1, wherein the weights (15) on the weight frame (14) can be increased or decreased by depending upon the requirement of the test.
6. The system and method (100) as claimed in claim 1, wherein the loading assembly (100) as a whole, is free to move vertically under the influence of its gravity but restrained to move laterally (horizontally in any direction) by means of guide sleeves (7) at corners.
7. The system and method (100) as claimed in claim 1, wherein the support frame (22) for the water chamber (19) connected to the base platform (6) and the supports (22) are configured to hold the water chamber (19) in position.

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