Towards the development of an in situ non-destructive method to control the quality of concrete-to-concrete interfaces

2010 ◽  
Vol 32 (1) ◽  
pp. 207-217 ◽  
Author(s):  
P. Santos ◽  
E. Júlio ◽  
J. Santos
Keyword(s):  
2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Anna Hoła

Abstract The article presents original methodology of testing the moisture content of brick walls in buildings. It was developed on the basis of own experience acquired during testing the moisture content in many excessively wet buildings erected in various historical periods. The tests were conducted using different methods, including non-destructive methods. To emphasize the importance of the problem, an overview of the methodology was preceded by a brief presentation of the causes and negative effects of excessive moisture and salinity in brick walls. In addition, the article is illustrated with an example of the effects of moisture content tests carried out according to the developed methodology on a facility from the fourteenth century. According to the author, knowledge of the presented methodology, and its application, should contribute to both the improvement of the quality of conducted research and the credibility of the obtained results.


Author(s):  
Saïdou Bamogo ◽  
David Y. K. Toguyeni ◽  
Fati Zoma ◽  
Mohamed Yerbanga

The method used to evaluate the quality of concrete in structures includes, among other things, compressive strength testing of specimens cast on site. This method has shortcomings due to the non-uniformity in their formulation processes of the concrete studied in laboratories and that of the structure on site and the tardiness in obtaining test results. This is why the development of reliable methods of non-destructive assessment of the compressive strength of concrete in situ is essential for a better performance assessment of structures.There are a multitude of non-destructive methods, but in this article, the ultrasonic pulse velocity (UPV) and the rebound hammer (RH) are the methods used as they are easy to get manipulate, accessible and permit fast access to results. Analyses using single and multiple linear regression methods have been carried out with the results from compression tests and measurements of pulse velocity and rebound indices carried out between February and April 2018 on over 90 specimen samples in total. This resulted in correlation equations for the in-situ estimation of the compressive strength of the concrete studied.


2016 ◽  
Vol 10 (2) ◽  
pp. 119-126
Author(s):  
Mahlinda Mahlinda ◽  
Fitriana Djafar

The main purpose of this research was to observer effect co-solvent type (n-Hexane, chloroform and without co-solvent)  toward yield and quality of biodiesel via in situ transesterification process using microwave irradiation. The process was studied at microwave power 450 watt, reaction time 4 minutes, methanol to seed ratio 25:1 and catalyst concentration 5%. The physicochemical parameters of the biodiesel produced such as viscosity, density and acid value were analysed and compared with the SNI 7182-2012 standard. The experimental result showed the maximum yield biodiesel 78,32% obtained by using co-solvent chloroform.Test result of physicochemical properties (viscosity, density and acid value) of biodiesel products using co solvent n-Hexane, chloroform and without co solvent showed that these products conform to the SNI 7182-2012 standars. The type of co-solvent only affectedon biodiesel yield dan not affected on biodiesel quality (viscosity, density and acid value).  ABSTRAKTujuan penelitian ini adalah untuk mempelajari pengaruh jenis co-solvent (n-Hexane, chloroform dan tanpa co-solvent) terhadap rendemen dan mutu biodiesel secara trasesterifikasi in situ menggunakan radiasi gelombang mikro. Proses dilakukan pada daya gelombang mikro 450 watt, waktu reaksi 4 menit, perbandingan berat metanol terhadap bahan baku 25:1 dan jumlah katalis 5%. Parameter fisiko kimia dari produk biodiesel seperti viskositas, densitas dan angka asam di analisa dan dibandingkan dengan standar SNI 7182-2012 tentang biodiesel. Hasil penelitian menunjukkan rendemen maksimum biodiesel sebesar 78,32% diperoleh dengan menggunakan co-solvent chloroform. Hasil pengujian  karakteristik fisiko kimia (viskositas, densitas dan angka asam) dari produk biodiesel menggunakan co-solvent n-Hexane, chloroform dan tanpa co-solvent menunjukkan bahwa semua parameter ini masih memenuhi standar SNI 1782-2012 tentang biodiesel. Jenis co-solvent hanya berpengaruh pada rendemen biodiesel dan tidak berpengaruh terhadap mutu biodiesel (viskositas, densitas dan bilangan asam).Kata kunci: co-solvent, in situ transesterifikasi, microwave, rendemen, mutu   


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