Gallery_1-Photos of mixed topics on Road Pavements – ROAD PAVEMENT FORENSIC ENGINEERING (RPFE)

Cracked and Deformed Recycled Asphalt Pavement (Van Reenen’s Pass, 1985)

Asphalt rutting-Poor Asphalt Mix-Unstable Mix due to poor design for expected traffic (N1, Bloemfontein)

Thin asphalt Surfacing seal failure owing to crushing and weak interface – aggravated by water

Crocodile Cracking of old thin asphalt surfacing, aggravated by water and traffic loading

Secret of construction of a proper G1 Crushed stone layer- Slushing of the G1 Base to get excess fines out for proper consolidation and hence density of the layer

Thin asphalt (~30 mm) Rutting from Channelised and bi-directional HVS Traffic loading at elevated temperatures (>35 degree C)

Asphalt Surfacing: Permanent Deformation-Channelised and bi-directional Traffic loading-Note tyre pattern imprint.

Stress-In-Motion (SIM) measured tyre Vertical Contact Stress-7-Axle Vehicle on N3, Heidelberg, 2003/4. 26 tyres were measured. Note the un-equal contact patterns between tyres. Darker red, the higher the contact stress.

High Temperature (>35 degree C) rutting test on BTB and asphalt surfacing-Wandering and bi-directional HVS Traffic (N2, South Coast)

Test pit showing top G1 Base layer – Crushed Dolomite-typical grey colour. G1 on cementitious subbase layer.

Single axle tyre footprints showing un-equal tyre loading. Note outer left tyre working extremely hard (very high contact stresses, compared to inner twin tyre, barely touching the road surface. Tyre will heat up, and eventually burst owing to over heating.

Test pit of a BTB pavement with two cementitious subbase layers. Note the good quality of construction, (N3, near Durban, 1986/7)

Fatigue Cracking of cementitious subbase layers under extreme HVS tyre loading – Wandering and bi-directional mode.

Pumping under HVS tyre loading, wet crushed cementitious base layer pavement.. Base layer failed in crushing in the dry state. Wandering and bi-directional HVS loading mode.

Cross Section-Bitumen Treated Base (BTB) and asphalt surfacing Pavement after HVS test. loading mode was wandering and bi-directional.

HVS test showing Lateral water Erosion under the BTB layer from the stabilised Berea Red Sand subbase layers, pushing BTB upwards outside HVS test section. Water was added on the side of HVS test section and penetrated into the interface, causing erosion of the top of the cementitious subbase layer. Caution to be taken when stabilising Berea red Sand in wet areas.

Stress-In-Motion (SIM) measured tyre Vertical Contact Stress-7-Axle Vehicle on N3, Heidelberg, 2003/4. 26 tyres were measured. Note the un-equal contact patterns between tyres. Darker red, the higher the contact stress. Note missing tyre on second last axle.., with inner tyre carrying the loading of twin tyres.

In-situ Multi Depth Deflectometer (MDD) in cementitious base and subbase pavement in-situ, after HVS testing (Rooiwal, 1988/89)

Longitudinal Crack with carbonation towards bottom of cementitious subbase layer in BTB and asphalt surfacing layer. Red areas showing good cementation (ph > 11) using the phenolphalien carbonation test. Note darker areas where water penetrated from the top through the crack into full pavement depth.

Carbonation of upper cementitious subbase layer (not coloured), directly under BTB and asphalt surfacing – using the phenolphalien test. (Van Reenen’s Pass, 1985)

Dry crushing failure in top cementitious base layer under extreme HVS tyre loading- Wandering and bi-directional loading mode.

Pothole after wet HVS test on crushed cementitious base pavement (Rooiwal, 1988/7)

Carbonation of upper cementitious subbase layer (not coloured), directly under BTB and asphalt surfacing – using the phenolphalien test. (Van Reenen’s Pass, 1985)

Granular Base failure in shear mode – typical shear failure (Mohr-Coulomb)

Poor maintenance (patching) and drainage on old pavement. Dangerous condition.

Technology Transfer – very important for training.

Stress-In-Motion (SIM) test Matrix: Vertical Contact Stress patterns of a single tyre under various tyre loading and tyre inflation pressures. Ideal case ~ 720 kPa, at 20 kN . This is indicative of overloading the tyre for a chosen inflation pressure.

Crushed and weak interlayer causing failure of new asphalt seal

Road Surface Deflection with RSD device and 80 kN axle load test truck.

Shear and crocodile cracking in both wheel paths.

Un-equal Truck loading=Un-equal tyre loading. This is a typical safety and tyre overloading contact problem !

Education is key..!!- Once a student, always a student..!

Weigh-in-Motion (WIM) of vehicles on a National Road- Quantification of tyre and axle loading crucial for pavement design-1

Weigh-in-Motion (WIM) of vehicles on a National Road- Quantification of tyre and axle loading crucial for pavement design-2

Traffic associated cracking in thin concrete base layer using HVS in wandering and bi-directional loading mode.

Multi deck Static Scale for trucks and heavy vehicles at a Weigh bridge on our National roads.

Gautrans Heavy Vehicle Simulator (HVS) testing on Concrete Pavement. For more information on HVSs click link below:

Weigh-in-Motion (WIM) of vehicles on a National Road- Quantification of tyre and axle loading crucial for pavement design-3

Gautrans HVS on concrete pavement with Joint-Activity-Meters (JAM)

Complete failure into brittle state- pothole after 1st rains

Final granular base layer before asphalt surfacing – let it dry to ~ 50% Optimum Moisture Content (OMC) before tack coat and surfacing.

FAST_Falling Weight Deflectometer-FWD_1- For road surface deflection basin (or bowl)

FAST_Falling Weight Deflectometer-FWD_2

Two HVS MK III machines on Test Site at UC Davis Campus, CA, USA

Cracked and sealed Concrete-Rigid-Pavement-California

HVS_MK VI-Mexico_2015

HVS_MK VI-Mexico_2015 with test carriage and test axles

Wirtgen Foamed-Bitumen_Paddle_Mixer-Mexico

Close-up: HVS_MK VI-Mexico_2015 with test carriage and test axles

CSIR HVS MK III (Former Gautrans)

Close-up: Test pit on road R25, Gauteng-1

Test pit on road R25, Gauteng-2

Traffic control during forensic road inspection test pit

Concrete Weigh-in-Motion (WIM) – RIGID SUPPORT STRUCTURE CRITICAL FOR ACCUARTE AXLE LOAD READINGS.

STATIC-TYRE-PRINT-ON-HOT-DAY-asphalt seal -DEFORMATION

Two HVSs stored at Gautrans

Gautrans HVS MK_IV at Gautrans

Dual-Tyre-Static-Footprint using paint and HVS tyre Loading

Pavement Design with DYNAMIC-CONE-PENETROMETER-DCP. Click link below for DCP low volume road design and associated free software.

Typical-Surfacing-Options-CAPSA-2015

SIM-MK-VI-Proto Type demonstrator

Light Weight Falling weight Deflectometer (LWD)

Close-up: LIGHT-WEIGHT-DEFLECTOMETER-LWD

ASTM Standard 8kg-Dynamic Cone Penetrometer (DCP) (South African original, 60 degree cone tip)

WIDE-BASE (WB) TYRE TESTING with HVS and SIM Pad device

WIDE-BASE-WB-TYRE TESTING with HVS-Channelised Trafficking

SIM_SURFACE-ROUGHNESS-80kN-SINGLE-TYRE-TEST

COMPRESSION FAILURE-THIN-CONCRETE

Preparation for traffic counting loops

Typical Cross-Section of rubber pneumatic tyre (SABS1550)

Effect of tyre inflation pressure under the same loading but different inflation pressures

Close-Up-single tyre extreme tyre loading

BW-SIM-TEST MATRIX-VERTICAL-CONTACT-STRESS of a single tyre at various loadings and tyre inflation pressures

BW-SIM-TEST MATRIX-LONGITUDINAL-CONTACT-STRESS of a single tyre at various loadings and tyre inflation pressures

BW-SIM-TEST MATRIX-LATERAL-CONTACT-STRESS of a single tyre at various loadings and tyre inflation pressures

Standard_40kN-Dual-Tyre-Vertical Contact Stress

Standard_40kN-Dual-Tyre-Lateral Contact Stress

Standard_40kN-Dual-Tyre-Longitudinal Contact Stress

Workshops-Seminars_RMPD-Tech-Transfer_Fortaleza-Brazil-2016

ZOAB ASPHALT SURFACING – URBAN ROAD-NETHERLANDS

HVS MKV-COSTA-RICA-2016

Tyre Stress-in-Motion (SIM)-MKVB Pad Device

RMPD-JOURNAL-BOOKS-INTERNATIONAL-PEER REVIEWED PAPERS since 1999. Click link below for Journal by Taylor & Francis Online

DUAL PAD SIM SYSTEM MK VB at Gautrans

TESTING ON SIM-SOLID-RUBBER-TYRE

MOUNTAIN PASS-SOUTH AFRICA-GORDONS-BAY-2017

Crocodile Cracking in both wheel paths – old dry surfacing seal

Parking lot- CROCODILE-CRACKING-COLD-WEATHER, ALPS.

CROCODILE-CRACKING-COLD-WEATHER-ALPS

STEEL DRUM COMPACTORS

DUAL SIM PAD-MK-VB

Crushing failure of very thin surface treatment on Stabilised base (HVS Testing)

Test pit showing Phenolphthalein Test for carbonated Stabilised Layers. Red layer showing relatively good cementation. Base layer seems to be fully carbonated and therefore potential poor strength.