Fine lateritic floor waterproofed with a geotextile layer impregnated with bituminous material—seeking to defend the base versus the activity of the water

From: Ground advancement Case Histories, 2015

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Lilian R. De Rezende, ... Ennio M. Palmeira, in Ground development Case Histories, 2015

16.2 Materials and also methods

16.2.1 Materials

The products selected for this examine were:

Fine lateritic soil discovered in the construction site

A mixture the the exact same fine soil v 2% (by wt) the lime CH-I—aiming to study the impacts of chemical stabilization

Fine lateritic soil waterproofed v a geotextile class impregnated through bituminous material—seeking to defend the base versus the action of the water

A quarry waste available in the region

A mixture of good lateritic floor (20%) v crushed absent (80%)


16.2.2 MethodsField exam sections

The experimental test sections studied room located in between stakes 126 and 163 of highway DF-205 West, in the commonwealth District (latitude 15°32′22″S, longitude 47°52′27″W), close to the city that Sobradinho, close to Brasilia, the country’s national capital. This highway has a low volume that traffic, approximately 200 vehicles a day, and before the paving occupational begun, it was functioning together an unpaved road. The highway subsoil consists of a porous clay as subgrade material. The annual average temperature in the region is 21 °C and also the annual average precipitation is 1300 mm, spread in two very well-defined seasons: the dry (between the month of April and August) and also the wet (between the months of September and March) seasons.

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The architecture of the pavement to be made by the Highway department of the federal District (DER-DF) and a granular basic of crushed rock floor was recommended for the whole project. The timeless design an approach of the Brazilian federal Highway department (DNIT) based on the use of California bearing proportion (CBR) test results was employed because that the structural style of the pavement. The same pavement geometry was adopted in the test sections where the different materials were provided to facilitate construction and interpretation of this sections’ performances.


The seven test part were constructed in august 1998 v a full length of 440 m, 2 tracks (3.5 wide each), and with shoulders 1.5 m wide. The structure was written of a base product compacted with Proctor intermediate energy with its surface subjected to a twin sealing treatment. The qualities of the basic layers were differed in the 7 test part monitored, as presented in Fig. 16.1 and also Table 16.1.

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SectionStakeLength (m)SubgradeBaseSurface food or overlay
1126–13080CutSoil–crushed rock mixture (1:4)Double-sealing treatment
2145–14980EmbankmentQuarry wasteDouble-sealing treatment
3149–15380EmbankmentFine soilDouble-sealing treatment
4153–15780CutSoil–lime mixture (2%)Double-sealing treatment
5157–15940CutFine soil v geotextile between base and also overlayDouble-sealing treatment
6159–16140CutFine soil v geotextile between subgrade and baseDouble-sealing treatment
7161–16340CutFine soil enveloped by geotextileDouble-sealing treatment

In the laboratory, the adhering to tests were performed, follow to specifications of Brazilian standards:

Grain size distribution tests

Liquid and also plasticity limits

Miniature compacted dry (MCT) tests

Compaction

Swelling

CBR

Suction

Scanning digital microscopy (SEM)

Difractometric X-rays

Chemical analysis


The results of the ar tests were provided for security control and in the analyses the the pavement structural behavior. During the building and construction of the sections, these field tests were lugged out on every layer that the pavement. ~ that, tests to be performed periodically come verify the habits of the pavement transparent time and to check out the impacts of climatic changes and traffic volume. The tests performed were the following:

Sand-cone device test

Nuclear thickness meter test

In situ CBR

Dynamic cone penetration (DCP)

Plate-load test

Benkelman beam

Falling weight deflectometer (FWD)

Pencel pressuremeter


Back-analyses

Using the data derived in the field tests, back-analyses were conducted to identify the values of the materials’ identical moduli. Utilizing the worths of the preferably displacement derived in the plate-bearing and also Benkelman beam tests, the moduli worths were identified using the SIGMA/W computer code (Geo-Slope, 1995). Utilizing the deflection containers obtained v the FWD test, the moduli worths were also assessed with the usage of the computer system program Laymod4 (Rodrigues, 2002).