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Technical Specifications
Published in Jan van ‘t Hoff, Art Nooy van der Kolff, Hydraulic Fill Manual, 2012
Jan van ‘t Hoff, Art Nooy van der Kolff
Comment: It should be noted that prior to the in situ density test, the test location should be excavated to the specified depth. It is therefore not practical (or safe) to have in situ density tests performed at depths larger than +/- 2 m. BS1377 Part 9, section 2.1 and 2.2 refer to the sand replacement method. Alternatively, surface nuclear density testing can be adopted. Please note that BS1377 Part 9 has partially been replaced by European standards.
The essential paving properties of soil, sand and stones
Published in Maxwell Lay, John Metcalf, Kieran Sharp, Paving Our Ways, 2020
Maxwell Lay, Metcalf John, Sharp Kieran
Compaction can be quantified by laboratory testing to measure the achieved density. This once required taking core samples which was slow, affected the work process and possibly compromised the impermeability of the pavement. Today there is a range of devices, such as nuclear density meters, that permit real-time non-destructive testing of achieved densities.123 As traffic loads increased and as construction equipment improved, it became necessary to increase the “given amount of compactive effort”.
Field data to investigate the impact of initial air-voids on the performance of bituminous pavements – a case study
Published in Road Materials and Pavement Design, 2023
Harshitha Vuthipalli, Sridhar Raju, Prasanta K. Sahu, Ravindra Rao Peachara
The loose bituminous mixture of nearly 75 kg was collected from the paving site when the construction was in progress. The bitumen was extracted using the Soxhlet apparatus [IS 13826 (Part 7): 1993] to assess the gradation, and the binder content. The extracted binder was used for testing the rheology. Nearly, 5 kg of loose mixture was used for measuring the maximum specific gravity of the mixture (Gmm) using the RICE apparatus. The remaining quantity of the mixture was compacted in a 1 m × 1 m × 0.3 m test pit, using a plate compactor, and the Bosch vibratory hand compactor to achieve 92% of Gmm. The density was checked using a pavement quality indicator (PQI), a non-nuclear density gauge. The cores were taken from the compacted layer for further testing to simulate the field condition. After compaction, the cores were taken from the test pit the following day for measuring the bulk specific gravity as per AASHTO T 166, and were named as M0.
Electron localisation control in dissociating
Published in Molecular Physics, 2020
Zhengmao Jia, Mingfeng Qin, Qingyang Yue, Yandong Peng
Figure 3(a) shows snapshots of the common logarithm of the electron-nuclear density distributions taken at the end of the simulation. From this figure one can find that a single UV pulse with a central wavelength of nm, a peak intensity of W/cm2 and a duration of fs will give rise to a symmetric spatial distribution with . Meanwhile, the electron localisation probability of the middle potential well is . populations of all the dissociation states are stabilised at the protons on both sides. Only populations of all the dissociation events are localised at the middle proton when stable. More importantly, the total ionisation probability is . Practically no electron is ionised away under the chosen UV pulse even though the total dissociation degree is as large as .
Soil moisture and density monitoring methodology using TDR measurements
Published in International Journal of Pavement Engineering, 2020
Habibullah Bhuyan, Alexander Scheuermann, Didier Bodin, Rolf Becker
Couple of possible reasons might be responsible for the observed difference between field observations and TDR measurements. Very small air gaps might be shaped in between the connection of rod probe and sensor head. Moreover, small differences in material types and gradation might cause differences. Furthermore, developed calibration function might not produce most accurate relationship due to inadequate data. In addition, sub-base layer was constructed one month earlier than the base layer; however, measurements were taken on the same time immediately after completing the base layer. Besides these, nuclear density gauge might not yield most accurate density information. Overall, field moisture decreased to some extent in the year 2016 compared to the previous year, however, density remained nearly constant. The moisture might decrease due to the evaporation of moisture from surface of road.