1. UKM Learning and Research Repository
2. PHD Thesis / Tesis PHD
3. Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

Title:	New prototype of concrete barriers using expanded polystyrene beads subjected to impact loads
Authors:	Hasan Jasim Mohammed (P67450)
Supervisor:	Muhammad Fauzi Mohd. Zain, Prof. Dr.
Keywords:	Concrete barriers Polystyrene beads Loads Concrete
Issue Date:	21-Feb-2017
Description:	Concrete barriers prevent vehicles from entering the opposite lane and running off the road. The existing design of concrete barriers is excessively solid, thereby causing undesirable vehicle deformation, injury, or even death to drivers upon vehicle impact, which then requires highway traffic closure. Decreasing the impact of vehicle collisions against concrete barriers can enhance safety. The design of concrete barriers must ensure the absorption of large amounts of energy released in collisions. This study aims to evaluate the existing concrete barrier design. It also aims to design and build a new concrete barrier (NCB) prototype. The proposed design features a new shape and comprises three parts. It is also equipped with an interlocking mechanism to connect the concrete barrier segments. A simulation assessment of vehicle-barrier impact is implemented using commercial LS-DYNA software to verify whether design suitability agrees with specified roadside evaluation criteria. The NCB design is then compared with existing models for validation. Four concrete barrier prototypes are tested. One model is the control model, which uses normal concrete in all parts. The three other models use expanded polystyrene (EPS) concrete and are produced by replacing 15%, 30%, and 45% of the coarse aggregate volume with EPS beads; the cement is substituted with 10% silica fume (SF). This composite concrete is used in the two outer parts, whereas normal concrete is used in the middle part. Four impact velocities strike each model at 50, 70, 100, and 130 km/h. Finally, finite elements method (FEM) is verified using the ANSYS program by comparing its results with those of the experimental prototype testing. Results show that the NCB can effectively contain and redirect collided vehicles by reducing vehicle damage. Results also demonstrate minimal lateral deflection, which can facilitate the connection between the NCB and the ground. The occupant compartment is not penetrated, in which case drivers and passengers are kept safe during accidents. Moreover, the NCB is found to be accurate within the criteria. Failure occurs only in the outer part, which faces the strike force; and such failure is not observed in the other parts. The EPS beads, used in EPS concrete, with percentages of 15% and 30% absorb the impact loads satisfactorily and are thus better than those with the percentage of 45%. Results demonstrate little lateral deflection with good energy dissipation of up to 93%. The EPS beads lead to low strains and facilitate impact force absorption, as presented in the experimental and FEM models. The NCB prototype is functional in roads and meets roadside requirements.,Certification of Master's/Doctoral Thesis" is not available
Pages:	308
Call Number:	TA440.M853 2017 3 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.