Deterministic Seismic Hazard Analysis in Thailand using Active Fault Data

To develop seismic design criteria for buildings, seismic hazard analysis is required to estimate the ground motion intensity with criteria such as peak ground acceleration (PGA). The seismic hazard can be analyzed by using two approaches: deterministic seismic hazard analysis (DSHA) and probabilistic seismic hazard analysis (PSHA). In these two approaches, the seismic hazard is evaluated from past earthquake events and active faults data. In Thailand, seismic hazard is classified in the low lying regions; however, in recently years, earthquakes have occurred frequently in the North of Thailand. To prevent and reduce damage due to earthquakes in the future, determination of seismic hazard is needed. This research proposes a deterministic seismic hazard map evaluated from nineteen active faults affecting Thailand. Two types of active faults are considered: first, an active fault in a subduction zone and second, a crustal fault. The seismic hazard is evaluated by using a ground motion prediction equation (GMPEs). Four GMPEs are weighted equally for seismic crustal fault, and two GMPEs are weighted equally for a seismic subduction zone. The hypocentral distance is used to evaluate the seismic hazard for all ground motion prediction equations. The Northern part and the Western part of Thailand are high seismic hazard regions, because there are active faults with the large possibility of earthquakes of a maximum magnitude. The seismic hazards in the North, West and Northeast of Thailand are about 0.60 g. The seismic hazard in Bangkok is about 0.25 g due to the Three Pagoda fault and Sri Sawat fault. The seismic hazard in the South of Thailand is about 0.40 g

Effect of Brick Types on Compressive Strength of Masonry Prisms

This study investigates brick types and masonry prisms under compressive loading according to ASTM C1314–14 as the basic parameters for evaluating lateral resistance of masonry infill walls and to compare compressive strength amongst various brick types. The lateral resistance capacity of a masonry infill wall model depends on the compressive strength of the masonry prism, and the lateral deformation of a masonry infill wall model depends on the strain at the maximum stress of the masonry prism. A masonry prism is an assemblage made of representative units (clay brick, hollow brick, lightweight block, etc), mortar and grout. In this research, eight types of brick are considered which are hollow brick, lightweight block and six types of clay brick. From the test results, the ductile behavior of a masonry prism under compressive loading means that it undergoes further deformation. The masonry prisms made of solid clay brick show the best performance with the largest average compressive stress of 10.8 MPa and largest cumulative energy dissipation of 444 kN/mm, but their behavior is non-ductile. The compressive stress of lightweight block is the weakest with the average compressive stress of 2.62 MPa. The compressive strengths of masonry prisms made of all clay brick types are higher than the compressive stresses of those made of hollow brick and lightweight block

Enhancement of tensile performance of concrete by using synthetic polypropylene fibers

The research attempted to investigate the effect of polypropylene fibers (PP fibers) on the mechanical characteristics of concrete. According to ASTM C39/C39M and ASTM C 1609/C1609M, standard testing methods were used to examine the concrete compressive and flexural strength, post-cracking behavior, and toughness. The mechanical properties were evaluated at different ages of concrete curing, namely 1 day, 7 days, and 28 days, and for different quantities of fiber volume portions, specifically 0.0%, 0.5%, and 1.0%. The results demonstrate that a fiber volume of 0.5% is the most effective in obtaining the highest compressive strength. The recorded values at the related testing ages were 31.07 MPa, 41.51 MPa, and 46.68 MPa. Additionally, the utilization of 0.5% and 1.0% volume of PP fiber in concrete resulted in improved flexural strength and post-cracking performance. The toughness values for these mixes were 2.0 and 2.6 times higher than those for the plain concrete. Upon analyzing the fracture surface, there was a homogeneous distribution of fibers, which played a significant role in enhancing the overall functionality of the concrete. The research validated that the inclusion of polypropylene fibers substantially enhanced the mechanical characteristics of concrete, emphasizing the potential of fiber reinforcement in concrete-based implementations

Enhancement of tensile performance of concrete by using synthetic polypropylene fibers

The research attempted to investigate the effect of polypropylene fibers (PP fibers) on the mechanical characteristics of concrete. According to ASTM C39/C39M and ASTM C 1609/C1609M, standard testing methods were used to examine the concrete compressive and flexural strength, post-cracking behavior, and toughness. The mechanical properties were evaluated at different ages of concrete curing, namely 1 day, 7 days, and 28 days, and for different quantities of fiber volume portions, specifically 0.0%, 0.5%, and 1.0%. The results demonstrate that a fiber volume of 0.5% is the most effective in obtaining the highest compressive strength. The recorded values at the related testing ages were 31.07 MPa, 41.51 MPa, and 46.68 MPa. Additionally, the utilization of 0.5% and 1.0% volume of PP fiber in concrete resulted in improved flexural strength and post-cracking performance. The toughness values for these mixes were 2.0 and 2.6 times higher than those for the plain concrete. Upon analyzing the fracture surface, there was a homogeneous distribution of fibers, which played a significant role in enhancing the overall functionality of the concrete. The research validated that the inclusion of polypropylene fibers substantially enhanced the mechanical characteristics of concrete, emphasizing the potential of fiber reinforcement in concrete-based implementations