scholarly journals Effect of Exhaust Gas on Natural Stone Tablets, a Laboratory Experiment

2018 ◽  
Author(s):  
Orsolya Farkas ◽  
Ákos Török
Keyword(s):  
Combustion Engine ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Operating Conditions ◽  
Natural Stone ◽  
Exhaust Emission ◽  
Exhaust Gas ◽  
Material Loss ◽  
Weight Density

8 different natural stone types were exposed to exhaust gas under laboratory conditions to assess urban stone damage. 3 cm in diameter cylindrical test specimens were made from travertine, non-porous limestone, limestone, rhyolite tuff, sandstone, andesite, granite and marble. The samples were exposed for 1, 2, 4 and 8 hours to exhaust gas that was generated by compression ignition internal combustion engine. The exhaust emission was measured. The operating conditions of the engine were documented and several parameters (weight, density, ultrasonic pulse velocity, capillary water absorption, porosity) were measured before and after exhaust gas exposure. The tests indicate that despite the deposition of soot on the surface a significant material loss was recorded at rhyolite tuff (2m%) and at andesite (1m%). The penetration depth of soot was also different for different lithologies. A correlation was found between the ultrasonic pulse velocity and density of tested stones.

Lightweight Geopolymer Concrete Containing Recycled Plastic Beads

2019 ◽  
Vol 801 ◽  
pp. 377-384 ◽  
Author(s):  
Athika Wongkvanklom ◽  
Patcharapol Posi ◽  
Sahalaph Homwuttiwong ◽  
Vanchai Sata ◽  
Ampol Wongsa ◽  
...  
Keyword(s):  
Fly Ash ◽  
Water Absorption ◽  
Sodium Hydroxide ◽  
Lightweight Concrete ◽  
Positive Impact ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
River Sand ◽  
Weight Density

Utilizing recycled plastic beads (RPB) as lightweight waste aggregates in the concrete and geopolymer application is quite attractive. This study presented the mechanical behavior, density, porosity, water absorption, abrasion resistance, thermal conductivity, and ultrasonic pulse velocity (UPV) of geopolymer lightweight concrete containing RPB. River sand in each mixture was replaced by various proportions of RPB ranging between 0-100% by weight. Sodium hydroxide concentration of 15 M, activator solution to fly ash ratio (L/A) of 0.40, sodium silicate and sodium hydroxide ratio of 1.0, and aggregate to fly ash ratio of 1.0 were used throughout the experiment. The results indicated that the replacement of sand by 25% and 50% of RPB had a positive impact on the weight, density, water absorption, and thermal insulating property. The strength and density of the concretes met the minimum requirements of structural lightweight concrete according to ASTM C330.

PENGKAJIAN KEKUATAN BETON STRUKTUR JEMBATAN PASCA KEBAKARAN

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Sudarmadi Sudarmadi
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Strength Assessment ◽  
Concrete Testing

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.

scholarly journals Correlation between Uniaxial Compression Test and Ultrasonic Pulse Rate in Cement with Different Pozzolanic Additions

2021 ◽  
Vol 11 (9) ◽  
pp. 3747
Author(s):  
Leticia Presa ◽  
Jorge L. Costafreda ◽  
Domingo Alfonso Martín
Keyword(s):  
Compression Test ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Uniaxial Compression Test ◽  
Unconfined Compression Test ◽  
Pozzolanic Cement ◽  
The Relationship ◽  
Compression Resistance

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.

scholarly journals Mechanical Characterisation and Shrinkage of Thermoactivated Recycled Cement Concrete

2021 ◽  
Vol 11 (6) ◽  
pp. 2454
Author(s):  
Sofia Real ◽  
José Alexandre Bogas ◽  
Ana Carriço ◽  
Susana Hu
Keyword(s):  
Mechanical Strength ◽  
Elasticity Modulus ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Cement Concrete ◽  
Supplementary Cementitious Material ◽  
Mechanical Characterisation ◽  
Shrinkage Behaviour ◽  
Binder Ratio

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.

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