The compressive strength and water absorption of cement mortars with different water-binder ratio (0.35, 0.45 and 0.55) and fly ash content (0, 10%, 20% and 30%) under water immersion were investigated, and the correlation between them was further analyzed. The internal microstructure and phase composition of mortar was studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The results show that the inside of mortar mixed with fly ash displayed the loose and porous microstructure. Therefore, the incorporation of fly ash reduced the compressive strength of mortar, especially the early strength, and the strength decreased with the increase of fly ash content, and the water absorption of mortar also increased. There was a linear correlation between the compressive strength and water absorption of mortar with the equation: fc = −3.838β + 62.332, where fc and β represented the compressive strength and water absorption, respectively. Therefore, when the water absorption of mortar immersed in water was measured, its corresponding compressive strength could be preliminarily inferred through this equation, which was of great significance for detecting and identifying the stability and safety of hydraulic structures.
& Materials, 710:83-90, 2014.
6. X. Qian, S. Zhang, S. Swaddiwudhipong, et al. Temperature dependence of material length scale for strain gradient plasticity and its effect on near-tip opening displacement. Fatigue & Fracture of Engineering Materials & Structures, 37(2):157-170, 2014.
7. R. Ghorbani, F. Matta, M. A. Sutton. Full-Field Deformation Measurement and Crack Mapping on Confined Masonry Walls Using Digital Image Correlation. Experimental Mechanics, 55(1):227-243, 2014.
8. Chu et al. Applications of digital-image-correlation
The selection of the formwork system for high rise building affects the entire construction project duration and cost. The study reports the factors influencing the selection of different formwork system in the construction of high rise buildings through structural questionnaire survey from the client, contractor, consultant, and interviews with expert members. Total of 40 technical factors was identified from the literature and 220 filled questionnaires were received from the respondent. Relative Importance Index method is used to find the topmost factors affecting the selection of formwork system. Additionally, from factor analysis 22 factors were identified to have a correlation with one another. Regression analysis reveals that duration of the project, maintenance cost, adaptability, and safety have impact on formwork selection across time, cost and quality. These findings could potentially increase the construction company’s existing knowledge in relation to formwork selection.
The main objective of the article is to present quantified and measurable risks likelihood appearance, impact and significance of inspected and monitored 48 commercial construction projects and their feasibility to be carried out. Original technical, financial and organisational feasibility studies in compliance with a rigorous Bank Investment Supervision requirements have been executed by the author in the period of 2005 – 2018. Methodology of construction project appraisal for financing and execution professional preparation have been laid out – technical documentation, arrangements, realisation. Analysis and assessment of Bank Investment Supervision consisted of project execution plan PEP, geotechnical and environmental conditions, permit design, agreements and decision impacts of local authorities, engineering contract for construction works, project insurance and performance bonds, schedule of execution tasks and their costs, payment plan, investment budget and project economical effectiveness, scope of monthly construction works execution assessed by Earned Value Method approach and handover procedure of construction project. An attempt was made to express numerically the relationship between risks impacts and their level of likelihood. Also, a method of associating the influence of projects risks impacts on the extent of the likelihood of project risk occurrence which makes possible to determine the direction and the strength of this relationship was presented. Finally, risks likelihood appearance, impact and significance variability of commercial construction projects within last two years of booming investment industry have been determined.
The paper presents the dependence of ITS results at the elevated temperature (40°C) on rutting parameters, i.e. proportional rut depth (PRDAIR) and wheel tracking speed (WTSAIR), obtained at the temperature of 60°C. The asphalt mixture samples were prepared in the gyratory compactor, but ITS tests were conducted with typical Marshall press, at a loading rate of 50 mm/min. Correlation analyses show a strong relationships between ITS results and rutting parameters, whereby the correlation coefficients obtained are higher for the PRDAIR parameter (r = −0.88) than WTSAIR (r = −0.81). Using the obtained regression functions, the prediction limits as well as confidence limits were calculated, which allowed to develop criteria for assessing resistance to rutting on the basis of ITS test, and taking into account the technical requirements in Poland.
O. Giuffrè, A. Granà, T. Giuffrè, R. Marino and S. Marino
13. O. GIUFFRÈ, A. GRANÀ, T. GIUFFRÈ, R. MARINO, Improving reliability of road safety estimates based on high correlated accident counts, Transportation Research Record, 2019, 197-204, 2007.
14. O. GIUFFRÈ, A. GRANÀ, F. CORRIERE, R. MARINO, Handling under-dispersion in calibrating Safety Performance Function at urban, four-leg, signalized intersections, Journal of Transportation Safety & Security, 3, 3, 174-188, 2011.
15. O. GIUFFRÈ, A. GRANÀ, T. GIUFFRÈ, R. MARINO, Accounting for Dispersion and Correlation in Estimating Safety
Vibration and Shock 33(11): 78-106, 2014.
18. X.H. Yu, “Probabilistic seismic fragility and risk analysis of reinforced concrete frame structures”, Doctor thesis, Harbin Institute of Technology, Harbin, 2012.
19. K. Faraji, M. Miri, “Correlation Between Damage Indexes in Knee Bracing Frames Subjected to Earthquakes” Advanced Materials Research 255-260, 2350-2354, 2011.
20. V.M. Zobin, F. Ventura-ramírez, C.L. Gutiérrez-andrade, L.H. Cruz, S. Santibáñez-ibáñez, “The Mw 7.4 Colima, Mexico, Earthquake of 21 January 2003: The Observed Damage Matrix in Colima
M. Maślakowski, K. Brzeziński, A. Zbiciak and K. Józefiak
The subject matter of this paper is assessment of the suitability of a dynamic cone penetrometer for determination of the state of soil. The principle of operation of the dynamic cone penetrometer, similar to commonly used DPL penetrometers, is described in the paper. Next the results of investigation conducted in Poland using a new dynamic cone penetrometer are presented. A series of measurements were performed in real field conditions. An attempt was made to correlate the results obtained with the dynamic and static cone penetrometers (CPT) respectively. These correlations were then subjected to validation to obtain a preliminary evaluation of the suitability of the dynamic cone penetrometer for determining the state of soil.