Concrete pavement structure comprising a concrete base layer and an elastomer improved concrete wearing layer
10815624 ยท 2020-10-27
Assignee
Inventors
- Duc Tung Dao (Saint-Quentin Fallavier, FR)
- Mohsen Ech (Saint-Quentin Fallavier, FR)
- Nicolas Miravalls (Saint-Quentin Fallavier, FR)
- Eric Stora (Saint-Quentin Fallavier, FR)
Cpc classification
E01C7/358
FIXED CONSTRUCTIONS
Y02A30/30
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
Abstract
A concrete pavement structure includes a base layer directly coated by a wearing layer, wherein the base layer is a concrete base layer and the wearing layer is an elastomer modified pervious concrete layer, having a thickness below to 4 cm, a void content ranging from 5% to 20% in volume, and a maximal diameter of aggregates present in the polymer modified pervious concrete layer is 10 mm.
Claims
1. A concrete pavement structure comprising a base layer directly coated by a wearing layer, wherein the base layer is a concrete base layer and the wearing layer is an elastomer modified pervious concrete layer, having a thickness less than 4 cm, a void content ranging from 5% to 20% in volume, and a maximal diameter of aggregates present in said elastomer modified pervious concrete layer is 10 mm.
2. The concrete pavement structure of claim 1, wherein the elastomer modified pervious concrete layer has a friction coefficient, measured by Wehner & Schulze method, WS, above 0.32, at 180,000 polishing cycles.
3. The concrete pavement structure of claim 1, wherein the concrete base layer is an undowelled pavement, jointed plain concrete pavement, jointed reinforced concrete pavement, continuously reinforced concrete pavement, or a low cost base layer.
4. The concrete pavement structure of claim 1, wherein the concrete base layer directly coated by the elastomer modified pervious concrete layer has compressive strength, at 28 days, above 20 MPa.
5. The concrete pavement structure of claim 1, wherein the set concrete base layer directly coated by the elastomer modified pervious concrete layer has flexural resistance strength, at 28 days, above 8 MPa.
6. The concrete pavement structure of claim 1, wherein the tensile bond strength between concrete base layer and elastomer modified pervious concrete layer is above 2.5 MPa.
7. The concrete pavement structure of claim 1, wherein the void content of the elastomer modified pervious concrete ranges from 5% to 10%, in volume.
8. The concrete pavement structure of claim 1, wherein the elastomer modified pervious concrete comprises, by m.sup.3 of fresh pervious concrete from 220 to 380 kg of a hydraulic binder; from 86 to 148 liters of water, the mass ratio weight of water/weight of hydraulic binder ranging from 0.3 to 0.5; from 1210 to 1720 kg of coarse aggregates having a diameter from 1.6 mm to 10 mm; from 30 to 520 kg of crushed or natural fine aggregate having a diameter from 0 mm to 2 mm; wherein all aggregates have maximal diameter, Dmax, equal or below 10 mm; and an elastomer.
9. The concrete pavement structure of claim 1, wherein, in the elastomer modified pervious concrete, coarse aggregates having a diameter from 1 mm to 10 mm and crushed sand having a diameter from 0 mm to 1 mm constitute from 80% to 100% by mass of all the aggregates.
10. The concrete pavement structure of claim 1, wherein the elastomer modified pervious concrete comprises a superplasticizer.
11. The concrete pavement structure of claim 1, wherein the elastomer is introduced under the form of a latex.
12. The concrete pavement structure of claim 10, wherein the elastomer is a copolymer of vinyl acetate-ethylene-(meth)acrylic acid esters.
13. The concrete pavement structure of claim 1, wherein, in the elastomer modified pervious concrete, the hydraulic binder is any ordinary Portland cement, CEM I, CEM II, CEM III, CEM IV, or CEM V as defined in the cement standard EN 197-1.
14. The concrete pavement structure of claim 1, wherein the concrete base layer is a roller compacted concrete.
15. A process for manufacturing a concrete pavement structure of claim 1, comprising directly depositing the elastomer modified pervious concrete layer on the concrete base layer before the hardening of said concrete base layer.
16. A road comprising the concrete pavement structure of claim 1.
17. A method for improving skid resistance of a pervious concrete layer comprising using an elastomer present in the pervious concrete layer and forming the elastomer modified pervious concrete layer in the concrete pavement structure of claim 1.
18. The concrete pavement structure of claim 1, wherein the low cost base layer is a Roller-Compacted Concrete or other low-cost slip-formed concrete.
19. The concrete pavement structure of claim 8, wherein the elastomer modified pervious concrete comprises, by m.sup.3 of fresh pervious concrete from 350 to 380 kg of a hydraulic binder.
20. The concrete pavement structure of claim 9, wherein, in the elastomer modified pervious concrete, coarse aggregates having a diameter from 1 mm to 10 mm and crushed sand having a diameter from 0 mm to 1 mm constitute from 90% to 100% by mass of all the aggregates.
21. The concrete pavement structure of claim 10, wherein the elastomer modified pervious concrete comprises a superplasticizer in content up to 5% by weight, on the basis of the hydraulic binder weight.
22. The concrete pavement structure of claim 11, wherein latex is styrene butadiene rubber emulsion, neoprene emulsion, acrylic acid emulsion, acrylate emulsion, styrene-acrylate emulsion, vinyl acetate-ethylene emulsion, acrylate-ethylene-vinyl ester emulsion, or mixture or two or more of said emulsions.
23. The road of claim 16, wherein the road is a highway.
Description
DETAILED DESCRIPTION OF FIGURES
(1)
(2)
(3) R=ReferenceADVA0.29% C1=0.145% ADVA-5% Etonis260
(4) C2=0.145% ADVA-10% Etonis260 C3=0.217% ADVA-5% Etonis850
(5) C4=0.217% ADVA-10% Etonis850 C5=0.145% ADVA-5% Primal CM 160
(6) C6=0.07% ADVA-10% Primal CM 160 C7=0.145% ADVA-10% ChrysoCim
(7)
(8) REF: without elastomer in pervious concrete layer
(9) LAT: with elastomer in pervious concrete layer
(10)
(11)
(12)
(13) Hydromedia R==ReferenceADVA0.29%; C7=0.145% ADVA10% ChrysoCim C2=0.145% ADVA-10% Etonis2
(14)
(15) reference Ifsttar_VTAC C2=0.145% ADVA-10% Etonis260
(16) R=ReferenceADVA0.29% C7=0.145% ADVA10% ChrysoCim
DETAILED DESCRIPTION OF THE INVENTION
(17) A subject of the invention is a concrete pavement structure 1 comprising a base layer 3 directly coated by a wearing layer 2, wherein the base layer 3 is a concrete base layer and the wearing layer 2 is an elastomer modified pervious concrete layer, having a thickness below to 4 cm, a hardened void content ranging from 5% to 20%, preferentially from 5% to 10%, in volume and the maximal diameter of the aggregates present in said polymer modified pervious concrete layer is 10 mm.
(18) directly coated means that the concrete pavement structure does not comprise a bonding layer or a tack layer between the concrete base layer 3 and the wearing layer 2.
(19) The terms course and layer will be used interchangeably.
(20) The terms wearing layer or wearing course are interchangeably used to designate the elastomer modified pervious concrete layer of the invention.
(21) Properties of the Concrete Pavement Structure 1:
(22) The concrete base layer 3 directly coated by an elastomer modified pervious concrete layer 2 has good mechanical performance.
(23) The combination of the invention allows manufacturing concrete roads which can support heavy load and dense traffic.
(24) In the invention, the wearing course 2 is well bonded to the concrete subbase 3. Accordingly, the wearing course 2 can be as thin as possible. This notably allows the wearing layer 2 to advantageously work in compressive mode under the loading of vehicles because the tensile strength of concrete is much lower than the compressive strength. Less stress occurs in the thin course. The durability of the course is improved and the longevity of the concrete pavement structure 1 can thus be improved.
(25) In addition, because of the economic reason, the thickness of this course is preferably not thicker than 4 cm. As a result, to respect these criteria, the Dmax of aggregate is less than 10 mm.
(26) The concrete pavement structure 1 has good mechanical strength (as flexural, compressive, modulus . . . ) resulting in longer service life. The concrete pavement structure 1, especially the elastomer modified pervious concrete layer 2, is more durable than that of very thin asphalt concrete (BBTM in French) without raveling, rutting, scaling during its service life.
(27) The wearing course 2 has a skid resistance comparable to BBTM, which confirm the safety of the concrete pavement structure 1. The drainable property of wearing course 2 helps to reduce the water splash and spray risks under rainy weather.
(28) The elastomer modified pervious concrete layer 2 has a friction coefficient, measured by Wehner & Schulze method, WS, preferably above 0.32, at 180 000 polishing cycles. In particular, the WS curves are presented in example. As can been noticed, the elastomer modified pervious concrete layer 2 has a friction coefficient similar to the one obtained with very thin asphalt concrete (BBTM in French).
(29) Accordingly, the wearing layer 2 has good skid resistance, similar to the one obtained with very thin asphalt concrete (commercial reference).
(30) In particular, the set concrete base layer 3 directly coated by an elastomer modified pervious concrete layer 2 has a compressive strength at 28 days above 20 MPa, advantageously above 25 MPa, more advantageously above 30 MPa. The compressive strength at 28 days, is preferably from 20 MPa to 50 MPa, advantageously from 25 MPa to 45 MPa, more advantageously from 30 MPa to 40 MPa.
(31) In particular, the elastomer modified pervious concrete layer 2 has a compressive strength at 28 days above 20 MPa, advantageously above 25 MPa, more advantageously above 30 MPa. The compressive strength at 28 days is preferably from 20 MPa to 50 MPa, advantageously from 25 MPa to 45 MPa, more advantageously from 30 MPa to 40 MPa.
(32) In particular, the set concrete base layer 3 directly coated by an elastomer modified pervious concrete layer 2 has a flexural strength at 28 days above 6 MPa, advantageously above 7 MPa, more advantageously above 8 MPa. The flexural strength at 28 days is preferably from 6 MPa to 15 MPa, advantageously from 7 MPa to 10 MPa, more advantageously from 8 MPa to 10 MPa.
(33) In particular, the elastomer modified pervious concrete layer 2 has a compressive strength at 28 days above 6 MPa, advantageously above 7 MPa, more advantageously above 8 MPa. The compressive strength, at 28 days, is preferably from 6 MPa to 15 MPa, advantageously from 7 MPa to 10 MPa, more advantageously from 8 MPa to 10 MPa.
(34) In particular, the set concrete base layer 3 directly coated by an elastomer modified pervious concrete layer 2 has (flexural resistance strength at 28 days)/(compressive strength at 28 days) ratio above 0.2, advantageously 0.35 or more. The ratio is preferably from 0.2 to 0.5, advantageously from 0.3 to 0.4.
(35) In particular, the elastomer modified pervious concrete layer 2 has (flexural resistance strength at 28 days)/(compressive strength at 28 days) ratio above 0.2, advantageously 0.35 or more. The ratio is preferably from 0.2 to 0.5, advantageously from 0.3 to 0.4
(36) The bonding strength between the two layers 2, 3 is good. The invention does not require the need of a bonding layer or a tack layer between the concrete base layer 3 and the elastomer modified pervious concrete layer 2. This reduces the total cost of the road.
(37) The tensile bond strength between concrete base layer 3 and elastomer modified pervious concrete layer 2 is advantageously above 2 MPa, more advantageously above 3 MPa. The tensile bond strength between concrete base layer 3 and elastomer modified pervious concrete layer 2 is advantageously from 2 MPa to 4 MPa, more advantageously from 3 MPa to 4 MPa.
(38) Such good tensile bond strengths can notably be obtained by using a wet-on-wet process, id est the elastomer modified pervious concrete layer 2 is poured and placed before the final setting time of the concrete base layer 3, or less preferentially a wet-on-dry process, id est the elastomer modified pervious concrete layer 2 is poured and placed after the final setting time of the concrete base layer 3.
(39) Accordingly, the concrete pavement structure 1 does not comprise a layer (bonding layer, tack layer, etc.) between the base layer 3 and the elastomer modified pervious concrete layer 2.
(40) To assure efficient superficial water drainage, the void content of the polymer modified pervious concrete ranges advantageously from 5% to 20%, preferentially from 5% to 10%, in volume.
(41) The concrete pavement 1 of the invention provides the following advantages: a good mechanical performance with a high ratio of Flexural/Compressive strength, a better scaling resistance versus conventional pervious concrete, a better raveling resistance, a good bonding strength to the subbase concrete without a tack coat, a good skid resistance, a good capacity of drainage, and a large range of aesthetic choice.
(42) The concrete pavement 1 is composed of: a concrete base layer 3, preferably a low cost base layer such as Roller-Compacted Concrete or other low-cost slip-formed concrete, and an elastomer modified pervious concrete layer 2.
These layers are disclosed in more details in the following.
Detailed Description of the Elastomer Modified Pervious Concrete Layer 2
(43) The elastomer modified pervious concrete layer is a very high quality thin surface layer.
(44) The thickness of the elastomer modified pervious concrete layer advantageously ranges from 2 cm to 4 cm.
(45) Such a thickness requires that the maximal diameter of the aggregates present in this layer is below 10 mm.
(46) Advantageously, the polymer modified pervious concrete comprises, by m.sup.3 of fresh pervious concrete: From 220 to 380 kg, advantageously from 255 to 380 kg, more advantageously from 350 to 380 kg, of a hydraulic binder; From 86 to 148 liters of water, the mass ratio weight of water/weight of hydraulic binder ranging from 0.3 to 0.5; From 1210 to 1720 kg of coarse aggregates having a diameter from 1.6 mm to 10 mm; From 30 to 520 kg of crushed or natural fine aggregate having a diameter from 0 mm to 2 mm; Wherein all aggregates have maximal diameter, Dmax, equal or below 10 mm; An elastomer.
(47) The mass ratio weight of water/weight of hydraulic binder advantageously ranges from 0.35 to 0.45, more advantageously is 0.4.
(48) The aggregates include calcareous, siliceous, and silico-calcareous materials. They include natural, artificial, waste and recycled materials. The aggregates may also comprise, for example, wood.
(49) Advantageously, coarse aggregates having a diameter from 1.6 mm to 10 mm and crushed or natural fine aggregate having a diameter from 0 mm to 2 mm constitute from 80% to 100%, advantageously from 90% to 100%, more advantageously 100%, by mass of all the aggregates.
(50) Advantageously, coarse aggregates have a diameter from 1.6 mm to 6 mm, more advantageously from 1.6 mm to 4 mm.
(51) Advantageously, the coarse aggregates have a stiffness, characterized by the coefficient of PSV higher than 50.
(52) Advantageously, natural or crushed fine aggregate has a diameter from 0 mm to 0.6 mm, more advantageously from 0 mm to 0.4 mm.
(53) Advantageously, the polymer modified pervious concrete comprises a superplasticizer, advantageously in content from 0% to 5% by weight, more advantageously from 0.1% to 2% by weight, on the basis of the hydraulic binder weight.
(54) The term superplasticizer as used in this specification and the accompanying claims is to be understood as including both water reducers and superplasticizers as described in the Concrete Admixtures Handbook, Properties Science and Technology, V.S. Ramachandran, Noyes Publications, 1984.
(55) A water reducer is defined as an additive which reduces the amount of mixing water of concrete for a given workability by typically 10-15%. Water reducers include, for example lignosulphonates, hydroxycarboxylic acids, carbohydrates, and other specialized organic compounds, for example glycerol, polyvinyl alcohol, sodium alumino-methyl-siliconate, sulfanilic acid and casein.
(56) Superplasticizers belong to a new class of water reducers which are chemically different to older water reducers and capable of reducing water contents by about 30%. The superplasticizers have been broadly classified into four groups: sulphonated naphthalene formaldehyde condensate (SNF) (generally a sodium salt); sulphonated melamine formaldehyde condensate (SMF); modified lignosulfonates (MLS); and others. More recent superplasticizers include polycarboxylic compounds such as polycarboxylates, e.g. polyacrylates. The superplasticizer is preferably a new generation superplasticizer, for example a copolymer containing polyethylene glycol as graft chain and carboxylic functions in the main chain such as a polycarboxylic ether. Sodium polycarboxylate-polysulphonates and sodium polyacrylates may also be used. Phosphonic acid derivatives may also be used. The amount of superplasticizer required generally depends on the reactivity of the cement. In order to reduce the total alkali content the superplasticizer may be used as a calcium rather than a sodium salt.
(57) Phosphonic acid derivatives may also be used. Sodium polycarboxylate-polysulphonates and sodium polyacrylates may also be used. The amount of superplasticizer required generally depends on the reactivity of the cement. In order to reduce the total alkali content the superplasticizer may be used as a calcium rather than a sodium salt. Other additives may be included in the composition according to the invention, for example, a defoaming agent (e.g. polydimethylsiloxane). These also include silicones in the form of a solution, a solid or preferably in the form of a resin, an oil or an emulsion, preferably in water. More particularly suitable are silicones comprising (RSiO0.5) and (R2SiO) moieties. In these formulae, the R radicals, which may be the same or different, are preferably hydrogen or an alkyl group of 1 to 8 carbon atoms, the methyl group being preferred. The number of moieties is preferably from 30 to 120.
(58) For practical reasons, the elastomer is advantageously added under the form of a latex, id est a water emulsion comprising the elastomer. The elastomer could also be introduced under powder form.
(59) The elastomer is advantageously styrene butadiene rubber emulsion, neoprene emulsion, acrylic acid emulsion, acrylate emulsion, styrene-acrylate emulsion, vinyl acetate-ethylene emulsion, acrylate-ethylene-vinyl ester emulsion, or mixture or two or more of these emulsions. The elastomer can also be a powder of vinyl acetate-ethylene.
(60) Advantageously, the elastomer is a copolymer of vinyl acetate-ethylene-(meth)acrylic acid esters, preferably under the latex form.
(61) The elastomer content preferably ranges from 1% to 20% by weight, preferably 3% to 15% by weight, compared to the total weight of hydraulic binder. When elastomer is used in the form of latex, the content thereof is calculated on the basis of the dry weight of the elastomer.
(62) The polymer modified pervious concrete advantageously comprises 160 to 260 liters, more advantageously comprises 190 to 260 liters, even more advantageously comprises 230 to 260 liters, for example 230 liters, of mix hydraulic binder and water, by m.sup.3 of fresh pervious concrete.
(63) A hydraulic binder is a material which sets and hardens by hydration, for example a cement, in particular Portland cement, sulfo-aluminate cement, belitic cement, sulfo-belitic cement and their mixtures.
(64) Portland cement is a clinker as defined in the norm NF EN 197-1, February 2001. Portland clinker is obtained by clinkering at high temperature a mixture comprising limestone and, for example, clay.
(65) Portland cement, or other cements, can be mixed with mineral additions. In an embodiment, the hydraulic binder is any ordinary Portland cement, CEM I, CEM II, CEM III, CEM IV, or CEM V as defined in the cement standard EN 197-1, February 2001.
(66) Mineral additions are, for example, slags (for example as defined in the cement standard NF EN 197-1 standard of February 2001, paragraph 5.2.2), pozzolans (for example as defined in the cement standard NF EN 197-1 standard of February 2001, paragraph 5.2.3), fly ash (for example as defined by the cement NF EN 197-1 standard of February 2001, paragraph 5.2.4), calcined shales (for example as defined by the cement NF EN 197-1 standard of February 2001, paragraph 5.2.5), calcium carbonate (for example limestone as defined by the cement NF EN 197-1 standard of February 2001, paragraph 5.2.6), silica fume (for example as defined by the cement NF EN 197-1 standard of February 2001, paragraph 5.2.7), metakaolin or mixtures thereof.
(67) The polymer modified pervious concrete is advantageously compacted, for example with a vibrating hammer.
(68) The polymer modified pervious concrete can comprise further additives, in particular pigments when a colored course is wanted.
(69) This wearing course aims to offer a thin interface between the structural function and the user perception. It will allow road management authorities to benefit from concrete economics of a rigid pavement: equivalent costs at construction level, no structural maintenance over the life time, (only surface maintenance, to be assessed).
Detailed Description of Concrete Base Layer 3
(70) The concrete base layer can be any kind of concrete layer, in particular undowelled pavement, jointed plain concrete pavement, jointed reinforced concrete pavement, continuously reinforced concrete pavement, or advantageously a low cost base layer such as Roller-Compacted Concrete or other low-cost slip-formed concrete.
(71) Low cost base layer such as Roller-Compacted Concrete or other low-cost slip-formed concrete are preferred, for evident cost reasons.
(72) In particular, the concrete base layer does not need to be porous.
(73) As an illustrative embodiment, the concrete base layer comprises, by m.sup.3 of fresh pervious concrete From 250 to 380 kg, advantageously 300 to 380 kg, more advantageously from 330 to 380 kg, of a hydraulic binder; From 87 to 171 liters, advantageously from 100 to 152 liters, more advantageously from 87 to 133 liters, of water, the mass ratio weight of water/weight of hydraulic binder ranging from 0.35 to 0.45; From 800 to 1400 kg, advantageously from 800 to 1000 kg, of coarse aggregates having a diameter from 10 mm to 32 mm; From 200 kg to 600 kg, more advantageously from 200 to 400 kg, of coarse aggregated having a diameter from 6 mm to 10 mm, From 600 to 1200 kg, advantageously from 800 to 1000 kg, of fine aggregates having a diameter from 0 mm to 6 mm,
Manufacturing Process:
(74) A subject of the invention is also a process for manufacturing a concrete pavement structure 1 of the invention, wherein the elastomer modified pervious concrete layer is directly deposited on the concrete base layer before the hardening of said concrete base layer.
(75) Accordingly, the process does not require including an additional layer to improve the bonding between the concrete base layer and the elastomer modified pervious concrete layer. The preferred method of construction is what is called wet-on-wet: the elastomer modified pervious concrete layer 2 is poured and placed before the final setting time of the concrete base layer 3.
(76) In a preferred embodiment, a concrete base layer is deposited following traditional methods. The road may have been prepared with one or many subbase layers (mainly aggregates). Subbase layers (5, 6) are typically made of a recipe of mixing different sizes of crushed rock together forming the aggregate. An aggregate is normally made from newly quarried rock, or it is sometimes allowed to be made from recycled asphalt concrete and/or Portland cement concrete.
(77) After deposition of the concrete base layer 3, but before final setting, the elastomer modified pervious concrete layer 2 is poured and placed on the concrete base layer 3. This process is called wet-wet process and allows good bonding strength.
(78) The principle of this method is placing a relatively thin, high-quality concrete surface immediately on top of a lower concrete layer when it is still plastic. For a good bonding to lower layer it is recommended to place the upper layer within 15 to 90 minutes (ideally within 60 minutes) of the lower concrete layer.
(79) The concrete layers 2, 3 can be dried cured; meaning that curing compound, plastic sheet may not be required. The hydraulic reaction of the binder does not require heat, catalyst of UV treatments.
(80) The layers can easily be colored, by well-known processes.
(81) Negative roughness of the top surface, enabling road comfort and safety, is achieved by using well known processes of placement such as a compaction made by a slippery device (roller, cylinder metal tube . . . ).
(82) In addition to the properties already disclosed, the concrete pavement structure of the invention is environment friendly (the use of additional chemicals is overall reduced) and gives a large aesthetic choice to authorities.
(83) The noise reduction is comparable to that of very thin asphalt concrete (BBTM).
(84) In term of costs, it is competitive with asphalt concrete.
(85) A subject of the invention is also a road comprising the concrete pavement structure 1 of the invention.
(86) This road is especially for vehicles traffic, including heavy load and dense traffic. In particular, the road is a highway.
(87) A further subject of the invention is use of an elastomer in an elastomer modified pervious concrete layer to improve skid resistance of the pervious concrete layer.
(88) The elastomer and elastomer modified pervious concrete layer are as disclosed above.
(89) In this specification including the accompanying claims: flexural strength values are measured after dry curing for seven days at 20 C., at 50% of relative humidity on prism-shaped test samples having a width of 4 cm and a height of 7 cm and a length of 16 cm; supported at two points, force being applied in the middle; the force applied to the sample is increased at a rate of 0.05 kN/sec during testing, percentages, unless otherwise specified, are by weight, bonding strength is measured by NF EN 1542 standard published in 1999, scaling is determined by the continuously follow-up of mass loss of cubic test samples of 10*10*10 cm which are immerged in a salt-water of 3% of NaCl during the free-thaw cycles according to the
(90) Method for Measuring the Void Content of Pervious Concrete Element
(91) The voids contend in the pervious concrete is computed from the weight and apparent volume of compacted concrete.
EXAMPLES
(92) In examples, materials are available to the following providers:
(93) TABLE-US-00001 CEM I 52.5 LafargeHolcim, Saint Pierre la Cour Coarse aggregates 1.6/3 LafargeHolcim, Cassis site (France) Fine aggregate 0/0.312 LafargeHolcim, Fulchiron site (France) Superplasticizer Grace Construction Products ADVA Flow 450 Latex Etonis 260 Wacker Polymers Powder Etonis 850 Wacker Polymers Latex Primal CM 160 Dow construction chemicals Latex ChrysoCim Chryso
(94) The different families of latex used are:
(95) TABLE-US-00002 TABLE 1 Used Name Chemical in mixes Etonis 260 Acrylic acid ester + ethylene + vinyl C1, C2 esters + water Etonis 850 Vinyl acetate/ethylene copolymer C3, C4 (powder) Primal CM 160 Acrylic emulsion polymer C5, C6 ChrysoCim Styrene butadiene emulsion C7
(96) The following concrete mixtures are used for testing:
(97) Wearing course:
(98) TABLE-US-00003 TABLE 2 Aggregates Crushed Free Void 1.6/3 sand 0/0.312 CEM I Super- water content Mix (kg/m3) (kg/m3) (kg/m3) plasticizer Elastomer w/c (L) (by volume) R 1675 104 305 3.0 0.0 0.4 121.9 17% C1 1650 103 302 1.5 27.2 0.4 120.4 21% C2 1650 103 286 1.4 51.5 0.4 114.0 18% C3 1650 103 284 2.1 14.2 0.4 113.3 21% C4 1650 103 255 1.9 25.5 0.4 101.8 19% C5 1650 103 301 1.5 30.1 0.4 120.1 16% C6 1650 103 284 0.7 56.9 0.4 113.5 21% C7 1650 103 283 0.0 61.5 0.4 112.8 20%
(99) For all, the volume of paste is 230 L/m.sup.3
(100) The concrete is, in any case, compacted by vibrating hammer.
(101) The concrete is, in any case, cured by dried curing at 50% HR at 20 C.
(102) Base Course:
(103) TABLE-US-00004 CEM I 52.5 LafargeHolcim, Saint Pierre la Cour Coarse aggregates 11/22 LafargeHolcim, Cassis site (France) Coarse aggregates 6/10 LafargeHolcim, Cassis site (France) Fine aggregates 0/5 LafargeHolcim, St Bonnet site (France)
(104) TABLE-US-00005 Coarse Coarse Fine aggregates aggregates aggregates 11/22 6/10 0/5 CEM I Free water Mix (kg/m.sup.3) (kg/m.sup.3) (kg/m.sup.3) (kg/m.sup.3) w/c (liter) RCC 1124.6 265.7 714.8 250 0.4 100
(105) Manufacturing Process of Concrete Pavement:
(106) The concrete is, in any case, compacted by vibrating hammer.
(107) The concrete is, in any case, cured by dried curing at 50% HR at 20 C.
(108) Results:
(109) Mechanical Strengths of the Wearing Course
(110) The results are provided in
(111) Bonding Strength
(112) The bonding strength to concrete base layer with 4 wet on wet scenario is compared: Without tack coat With a cement paste tack coat With a latex tack coat With segregation
(113) The results are provided in
(114) REF: without elastomer in pervious concrete layer
(115) LAT: with elastomer in pervious concrete layer
(116) The best results are obtained without tack coat.
(117) The tensile bond strength is very good, and there is no need to add a tack coat (or a bonding layer) between the concrete base layer and the elastomer pervious concrete layer.
(118) Raveling at 28 Days
(119) The results are provided in
(120) In comparison to Hydromedia (Vpaste=160 L, W/C=0.34, disclosed in WO2012/001292) the raveling is improved.
(121) Scaling (Cold Weather Condition)
(122) The freeze thaw cycle is disclosed in
(123) The addition of latex improved significantly the scaling resistance of pervious concrete.
(124) In comparison to Hydromedia (Vpaste=160L, w/c=0.34, disclosed in WO2012/001292) the scaling is improved.
(125) Skid Resistance
(126) The results are provided in
(127) The wearing layer of the invention has been compared to a very thin asphalt layer, described in the paper of Friel et al. (Use of Wehner Schulze to predict skid resistance of Irish surfacing materials, Shaun FRIEL, Malal Kane, David WOODWARD). In
(128) The skid resistances are comparable.
(129) The addition of latex increased skid resistance.