scholarly journals Effect of Dispersed Reinforcement on Ultrasonic Pulse Velocity in Stabilized Soil

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6951
Author(s):  
Maciej Miturski ◽  
Wojciech Sas ◽  
Algirdas Radzevičius ◽  
Raimondas Šadzevičius ◽  
Rytis Skominas ◽  
...  

One of the fundamental techniques for road subgrades is soil stabilization. Considering the high emission of carbon dioxide during the production of binders, novel techniques to reduce the binder are being studied. Thus, we investigated dispersed reinforcement in stabilized soils. A study was conducted to determine the ultrasonic pulse velocity in nine mixtures of soil, cement, and polypropylene fibers and then correlate the results with other destructive tests. The results show a decrease in wave velocity in mixes with fiber addition by up to 18.5%. The result is dependent on the curing time and whether the samples were stored in a water tank. Immersion in water increases the obtained results by about 6.3%. Based on the analysis, for mixtures with fibers, boundary velocities of waves above which lower values of modulus of elasticity were obtained were determined. Depending on the mix and the module analyzed, the limits range from 2194 m/s to 2498 m/s.

Author(s):  
Amit Kumar ◽  
◽  
Dharmender Kumar Soni ◽  

Although many techniques are available for the evaluation of soil parameters, but a quick and efficient method is always welcome. To avoid the hassle calculation and tedious procedures of testing; practitioners seek a fast method for site implementation of laboratory results. In the recent era of development and technology, it has been necessary to adopt the advanced techniques to evaluate the geotechnical parameters. In the present study, correlations between geophysical and compaction tests results have been derived. Eggshell powder (ESP), a waste material along with sodium chloride (NaCl) and polypropylene fiber (PPF) was used to stabilize the soil. Design of experiments was done by Taguchi technique using Minitab 17 software. A series of non-destructive geophysical tests i.e., Ultrasonic pulse velocity (UPV) and Electrical resistivity (Re) tests was carried out on 21 days aged soil specimens. Not only software based analytical results showed ESP as the dominating factor for attaining improvement in packing of soil particles and make soil resistive but also the results confirmed the same. UPV of the stabilized soil was found increased up to 69%-122% with respect to an increase in dry density of about 1.16%-1.74%. The utility of the present study can be found in places where dense soil and electric resistive properties meets such as transmission lines and railway electric poles etc. and for the purpose seismic and resistivity mapping methods can be used


2021 ◽  
Vol 56 (5) ◽  
pp. 90-106
Author(s):  
Taufiq Rochman ◽  
Suhariyanto

This study aims at the structural evaluation of the elevated concrete water tank condition, including crack initiation, through nondestructive testing. The growing demands for environmental quality have resulted in a rise in the design and construction of tanks and reservoirs in the construction industry. Cracks for water line leakage were found during watertight testing in concrete tanks. Long-term liquid leaking may permanently damage the tank and can contaminate the groundwater. Given the critical existence of leaked cracks in tank serviceability and durability, the contribution examines the triggers and effects of their occurrence. An inspection of the existing water tank system is conducted to ascertain its condition. The investigation included structural design checks, concrete compressive strength tests, visual assessments, hammer inspections, and Ultrasonic Pulse Velocity (UPV) testing with Portable Ultrasonic Non-Destructive Digital Indicating Tester (PUNDIT). This observation is made at many elevations on various sampling points on the tank structure's elements, including columns, beams, tank floor slabs, and tank wall shells. The results indicate the presence of flexural type cracks in the main beam's middle span and diagonal beams. Additionally, cracks attributed to long-term drying shrinkage were discovered on the diagonal of the floor slab and cracks of the same pattern on the main beam's middle span. The deflection estimated by structural remodeling was larger than the deflection estimated by design. The computed crack width in the main and diagonal beam exceeds the acceptable crack width.


2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Sudarmadi Sudarmadi

In this paper a case study about concrete strength assessment of bridge structure experiencing fire is discussed. Assessment methods include activities of visual inspection, concrete testing by Hammer Test, Ultrasonic Pulse Velocity Test, and Core Test. Then, test results are compared with the requirement of RSNI T-12-2004. Test results show that surface concrete at the location of fire deteriorates so that its quality is decreased into the category of Very Poor with ultrasonic pulse velocity ranges between 1,14 – 1,74 km/s. From test results also it can be known that concrete compressive strength of inner part of bridge pier ranges about 267 – 274 kg/cm2 and concrete compressive strength of beam and plate experiencing fire directly is about 173 kg/cm2 and 159 kg/cm2. It can be concluded that surface concrete strength at the location of fire does not meet the requirement of RSNI T-12-2004. So, repair on surface concrete of pier, beam, and plate at the location of fire is required.


2021 ◽  
Vol 11 (9) ◽  
pp. 3747
Author(s):  
Leticia Presa ◽  
Jorge L. Costafreda ◽  
Domingo Alfonso Martín

This work aims to study the relationship between the compression resistance and velocity from ultrasonic pulses in samples of mortars with 25% of pozzolanic content. Pozzolanic cement is a low-priced sustainable material that can reduce costs and CO2 emissions that are produced in the manufacturing of cement from the calcination of calcium carbonate. Using ultrasonic pulse velocity (UPV) to estimate the compressive resistance of mortars with pozzolanic content reduces costs when evaluating the quality of structures built with this material since it is not required to perform an unconfined compression test. The objective of this study is to establish a correlation in order to estimate the compression resistance of this material from its ultrasonic pulse velocity. For this purpose, we studied a total of 16 cement samples, including those with additions of pozzolanic content with different compositions and a sample without any additions. The results obtained show the mentioned correlation, which establishes a basis for research with a higher number of samples to ascertain if it holds true at greater curing ages.


2021 ◽  
Vol 11 (6) ◽  
pp. 2454
Author(s):  
Sofia Real ◽  
José Alexandre Bogas ◽  
Ana Carriço ◽  
Susana Hu

This paper investigates the mechanical and shrinkage behaviour of concrete with recycled cement (RC) thermoactivated from waste cement paste and waste concrete. Overall, compared to ordinary Portland cement (OPC), for the same water/binder ratio, the mechanical strength and ultrasonic pulse velocity were not significantly influenced by the incorporation of RC. The elasticity modulus decreased with the addition of RC and the shrinkage tended to increase at high RC content. The incorporation of up to 15% RC allowed the production of workable concrete with identical shrinkage and similar to higher mechanical strength than concrete with only OPC. RC proved to be a very promising more eco-efficient supplementary cementitious material.


Sign in / Sign up

Export Citation Format

Share Document