A simple method for predicting the characteristics of storms for the desogn of drainage structures in East Africa is described. The variation of a 2 year daily point rainfall, and the 10:2 year ratio for daily rainfall, over East Africa are given in map form. Using these, daily point rainfall for any return frequency can be calculated. To arrive at the design storm the daily point rainfall is a…
The requirements for waterproofing materials have been studied, both in the Laboratory and on bridge sites, against requirements for adhesion, stability and thermal properties. Laboratory experiments to evaluate the resistance of the membrane system to substrate cracking and damage, by constructional work, at 10 degrees and 20 degrees Celcius have been developed and standards of performance pro…
Two experimental orthotropic deck panels were studied while subjected to normal traffic on a trunk road. The behaviour of 38 mm mastic asphalt and 9mm resin-based surfacings were compared. The stresses generated by moving vehicles were measured and found to be considerably reduced on the panel surfaced with asphalt relative to the panel surfaced with resin-based materials. The composite action …
Tests with conventional cars at a nominal impact speeds of 8, 16 and 24 km/h showed that while the adult pedestrian folded over on to the bonnet before falling off, the child was knocked down. Reducing the height of the bonnet sufficiently to pick up the child causes the adult to strike the windscreen. The simplest method of reducing pedestrian injury is to adopt a front-end which provides opti…
Many local Authorities now incinerate their domestic refuse to reduce the demand for tipping space; nearly a million tonnes of residues from the process are currently being produced each year. This report, the fourth in a series on waste materials, gives the results of a recent programme of research to assess the potentialities of incinerated refuse for roadmaking. The investigation shows that …
The temperature history of four small experimental pavements laid adjacent to the full-scale road experiment at Alconbury By-Pass has been studied in detail. Temperatures in the pavements have been recorded at depths of 20 mm, 40mm, 100 mm, 200 mm and 350mm. There is little major difference in the temperature behaviour of the four constructions. Representative elements of the history of one of …
Experiments were carried out to determine the effect of discontinuities on the propagation of ultrasonic waves in samples of chalk and sandstone obtained from tunnel sites at Chinnor, Oxfordshire and Warrington, Cheshire respectively. In particular the effect of normal stress across a closed discontinuity was investigated. Tests to determine the wave velocity, attenuation coefficients and the e…
The report describes traffic flow observations made at five three-way major/minor priority junctions under conditions of heavy minor road demand. The results have been analysed by linear regression methods to determine the extent of the interactions between the major and minor road streams. Variations in the composition of major road traffic had no detectable effect on the total flow through th…
Surface dressings are known to afford a cheap and rapid method of renewing texture on bituminous roads and this Report reviews five full-scale road experiments designed to test the effectiveness of the technique on heavily-trafficked concrete roads as an alternative to grooving. The research has demonstrated the feasibility of applying single surface dressings to ungrooved roads carrying over …