Measurement Error Models (MEMs) Regression Method to Harmonize Friction Values from Different Skid Testing Devices

Skid measurement errors are unavoidable for each kind of skid testing device. The simple linear regression (SLR), used worldwide to harmonize friction measuring devices, does not consider that measurement errors affect both devices. For this reason, its use provides a biased estimate of the relationship between devices. The measurement error models (MEMs) regression method is proposed as a better method to harmonize any two skid testing devices. Regression according to both the SLR and MEM approaches have been performed with repeated measurements (from the same device) and between measurements obtained from two different skid testing devices. A comparison of the results is shown; MEM regression appears to be a more appropriate tool to harmonize friction measuring devices than SLR

Evaluation of variability of macrotexture measurement with different laser-based devices

The comparison of macrotexture values estimated from different measuring techniques, usually provides poor agreement and unsatisfactory confidence on the real macrotexture estimates by means of the Mean Texture Depth (MTD) Index. For this reason a new algorithm, to evaluate a more reliable 3D macrotexture index evaluated directly from 2D profile, has been proposed. This algorithm includes a profile data cleaning process, developed to detect and remove invalid laser readings present on pavement profile data recorded by means of a high speed laser device (HSLD). Preliminary results obtained on pavements of Virginia Smart Road seem promising

Measurement Error Models (MEM) regression method to Harmonize Friction Values from Different Skid Testing Devices

Skid measurement errors are unavoidable for each kind of skid testing device. The Simple Linear Regression (SLR), used worldwide to harmonize friction measuring devices, does not consider that measurement errors affect both devices. For this reason its use provides biased and not unique estimate of the relationship between devices. The Measurement Error Models (MEM) regression method is proposed as a better method to harmonize any two skid testing devices. SLR and MEM regressions between repeated measurements (from the same device) and between measurements obtained from two different skid testing devices are performed. A comparison of the results is shown and MEM regression appears to be a more appropriate tool to harmonize friction measuring devices instead of SLR

Measurement Error Models (MEM) regression method to Harmonize Friction Values from Different Skid Testing Devices

Skid measurement errors are unavoidable for each kind of skid testing device. The Simple Linear Regression (SLR), used worldwide to harmonize friction measuring devices, does not consider that measurement errors affect both devices. For this reason its use provides biased and not unique estimate of the relationship between devices. The Measurement Error Models (MEM) regression method is proposed as a better method to harmonize any two skid testing devices. SLR and MEM regressions between repeated measurements (from the same device) and between measurements obtained from two different skid testing devices are performed. A comparison of the results is shown and MEM regression appears to be a more appropriate tool to harmonize friction measuring devices instead of SLR

Maintenance for Repaired RC Column Exposed to Chloride Attack Based on Probability Distribution of Service Life

Abstract Chloride attack is one of the most critical deterioration due to rapid corrosion initiation and propagation which can cause structural safety problem. Extended service life through repairing is very important for determination of maintenance strategy. Conventionally adopted models for estimation of life cycle cost have shown step-shaped elevation of cost, however the extension of service life is much affected by quality of construction and repairing materials, which means engineering uncertainties in residual service life. In the paper, reinforced concrete column with three different mix proportions exposed to chloride attack are considered, and repairing numbers with related costs are evaluated through probabilistic technique for maintenance. With a given exposure condition, service lives with normal probabilistic distribution are considered, and the effect of design parameters such as coefficient of variation of service life and 1st repairing timing are investigated. The comparison of results from conventional approach (step-function) and probabilistic approach are performed. When calculating repair frequency for intended service life through probabilistic model, the required repair frequency is evaluated to be 6.71 times for OPC, 4.09 times for SG30, and 2.95 times for SG50, respectively. The probabilistic model for repairing cost is evaluated to be effective for reducing the repair frequency reasonably with changing the intended service life and design parameters