Cahit Bilim

Predicting the compressive strength of ground granulated blast furnace slag concrete using artificial neural network

In this study, an artificial neural networks study was carried out to predict the compressive strength of ground granulated blast furnace slag concrete. A data set of a laboratory work, in which a total of 45 concretes were produced, was utilized in the ANNs study. The concrete mixture parameters were three different water-cement ratios (0.3, 0.4, and 0.5), three different cement dosages (350, 400, and 450kg/m^3) and four partial slag replacement ratios (20%, 40%, 60%, and 80%). Compressive strengths of moist cured specimens (22+/-2^oC) were measured at 3, 7, 28, 90, and 360 days. ANN model is constructed, trained and tested using these data. The data used in the ANN model are arranged in a format of six input parameters that cover the cement, ground granulated blast furnace slag, water, hyperplasticizer, aggregate and age of samples and, an output parameter which is compressive strength of concrete. The results showed that ANN can be an alternative approach for the predicting the compressive strength of ground granulated blast furnace slag concrete using concrete ingredients as input parameters.

ÇELİK LİFİN ULTRA YÜKSEK DAYANIMLI HARÇLARIN MEKANİK ÖZELLİKLERİNE ETKİSİ

Bu calismada, ultra yuksek dayanima sahip olacak sekilde uretilen harclarin mekanik ozellikleri uzerinde celik lif katkisinin etkisi arastirilmistir. Harc icerisinde 0-1 mm ve 1-3 mm olmak uzere iki farkli boyuta sahip yuksek dayanimli kuvars agregasi ile beraber Portland cimentosu, silis dumani ve yuksek firin curufu kullanilmistir. Celik lif ise harc karisimlari icerisine hacimsel olarak %0, %0.5, %1, %1.5 ve %2 oranlarinda dahil edilmistir. Daha sonra, hazirlanan bu harclardan 40 x 40 x 160 mm boyutlarina sahip harc numuneler uretilmis ve bu prizmatik orneklerin 21 ± 1 °C sicakliktaki su kuru sonrasindaki 7, 14 ve 28 gunluk egilme ve basinc mukavemetleri tespit edilmistir. Calismadan elde edilen deneysel bulgular, celik tel katkisinin harc mekanik ozelliklerinin gelismesinde oldukca etkili oldugu ve celik lif oranindaki artisla birlikte ultra yuksek dayanimli harcin egilme ve basinc mukavemetinde kayda deger artislarin meydana geldigi belirlenmistir.

Influence of Clinoptilolite Replacement on Durability of Cement Mortars

AbstractThis paper presents the experimental results of a study on the durability properties of clinoptilolite blended cement mortars. In the study, clinoptilolite was used at 0, 5, 10, 15, 20, and 30% replacement by weight of cement while sand and water quantities were kept constant. Fire resistance, abrasion resistance, and shrinkage of the mortars were examined. The results showed that the replacement of cement with clinoptilolite in mortar improved the fire resistance of mortar and that water cooling resulted in higher strength losses than air cooling. Also, the abrasion resistance of mortars increased with an increase in the content of clinoptilolite. After the abrasion tests with a full 352 cycles, although the abrasion loss of control mortar was 2.83%, the abrasion losses of the mortars containing clinoptilolite ranged from 2.12 to 2.81% and the lowest abrasion loss was obtained from the mortars including 30% clinoptilolite. However, the incorporation of clinoptilolite in the mixture caused some in...