Different reinforced cement concrete design pdf packing models for concrete design are reviewed and compared. Andersen particle packing model is used to design UHPFRC. A dense skeleton of UHPC with a relatively low binder amount is produced.
The properties of the optimal designed UHPFRC are assessed. One simple and efficient method for producing the UHPFRC is utilised in this study. The workability, air content, porosity, flexural and compressive strengths of the designed UHPFRC are measured and analyzed. The results show that by utilizing the improved packing model, it is possible to design UHPFRC with a relatively low binder amount.
Additionally, the cement hydration degree of UHPFRC is calculated. The results show that, after 28 day of curing, there is still a large amount of unhydrated cement in the UHPFRC matrix, which could be further replaced by fillers to improve the workability and cost efficiency of UHPFRC. Check if you have access through your login credentials or your institution. RC structures using some favorable values of the most influential design parameters firstly, and then to compare the service life thus obtained with that of RC structures designed using a standardized approach. 1 for XC4 exposure class.
The sensitivity analysis results are discussed in detail including influence trends, importance ranking, non-monotonic effects and parameter interaction influences. 1, the service life of the RC structure is significantly improved. The choice of a concrete mix depends on the need of the project both in terms of strength and appearance and in relation to local legislation and building codes. The design begins by determining the requirements of the concrete.
These requirements take into consideration the weather conditions that the concrete will be exposed to in service, and the required design strength. The compressive strength of a concrete is determined by taking standard molded, standard-cured cylinder samples. Many factors need to be taken into account, from the cost of the various additives and aggregates, to the trade offs between the “slump” for easy mixing and placement and ultimate performance. The method of mixing will also be specified, as well as conditions that it may be used in. This allows a user of the concrete to be confident that the structure will perform properly. Various types of concrete have been developed for specialist application and have become known by these names. Concrete mixes can also be designed using software programs.
Such software provides the user an opportunity to select their preferred method of mix design and enter the material data to arrive at proper mix designs. Concrete has been used since ancient times. Besides volcanic ash for making regular Roman concrete, brick dust can also be used. The ingredients in any particular mix depends on the nature of the application. MPa rating than structural concrete. Many types of pre-mixed concrete are available which include powdered cement mixed with an aggregate, needing only water.
C ratios and the use of silica fume make concrete mixes significantly less workable, which is particularly likely to be a problem in high-strength concrete applications where dense rebar cages are likely to be used. Aggregate must be selected carefully for high-strength mixes, as weaker aggregates may not be strong enough to resist the loads imposed on the concrete and cause failure to start in the aggregate rather than in the matrix or at a void, as normally occurs in regular concrete. After sufficient hardening, the surface is cleaned and generally sealed to provide protection. The wear resistance of stamped concrete is generally excellent and hence found in applications like parking lots, pavements, walkways etc. While all high-strength concrete is also high-performance, not all high-performance concrete is high-strength. UHPC is characterized by being a steel fibre-reinforced cement composite material with compressive strengths in excess of 150 MPa, up to and possibly exceeding 250 MPa. UHPC is also characterized by its constituent material make-up: typically fine-grained sand, silica fume, small steel fibers, and special blends of high-strength Portland cement.