Hui-Mi Hsu

Engineering Properties and Correlation Analysis of Fiber Cementitious Materials

This study focuses on the effect of the amount of silica fume addition and volume fraction of steel fiber on the engineering properties of cementitious materials. Test variables include dosage of silica fume (5% and 10%), water/cement ratio (0.35 and 0.55) and steel fiber dosage (0.5%, 1.0% and 2.0%). The experimental results included: compressive strength, direct tensile strength, splitting tensile strength, surface abrasion and drop-weight test, which were collected to carry out the analysis of variance to realize the relevancy and significance between material parameters and those mechanical properties. Test results illustrate that the splitting tensile strength, direct tensile strength, strain capacity and ability of crack-arresting increase with increasing steel fiber and silica fume dosages, as well as the optimum mixture of the fiber cementitious materials is 5% replacement silica fume and 2% fiber dosage. In addition, the Pearson correlation coefficient was conducted to evaluate the influence of the material variables and corresponds to the experiment result.

Development of a Road Monitoring and Reporting System Based on Location-Based Services and Augmented-Reality Technologies

To provide a certain level of serviceability, road authorities need to perform appropriate and timely maintenance and rehabilitation (M&R) activities. However, the vast expanse and different deterioration properties of road systems greatly increase the complexity of M&R activities. Because of lack of funding and resources, it is almost impossible for road engineers to monitor every road and to promptly maintain and rehabilitate any defects that have been identified. Therefore, the monitoring and reporting of defects by the public are becoming indispensable. For several years, location-based services (LBSs) have been applied to mobile devices with mobile positioning functions to provide users with location-specific services. Augmented reality (AR) can support users in manipulating virtual objects in real environments. In this study, a road monitoring and reporting system (RMRS) is developed including a mobile RMRS (an Android application) on smartphones and a web-based RMRS by integrating LBS and AR technologies. By using LBS and AR technologies, the time and costs of M&R activities can be significantly decreased, because routes of M&R activities can be planned in advance and the neighboring defects can be instantly identified and processed, which conforms exactly to the current policies of the Public Oversight of Public Works Projects and Smooth Roads Project in Taiwan. By using field data from Ilan County in Taiwan and considering the indefinite delivery contract, different strategies for M&R operations derived from the mobile and web-based RMRSs are analyzed. The results are presented to demonstrate the system’s benefits, costs, and feasibility.

A Study of Crystalline Mechanism of Penetration Sealer Materials

It is quite common to dispense a topping material like crystalline penetration sealer materials (CPSM) onto the surface of a plastic substance such as concrete to extend its service life span by surface protections from outside breakthrough. The CPSM can penetrate into the existing pores or possible cracks in such a way that it may form crystals to block the potential paths which provide breakthrough for any unknown materials. This study investigated the crystalline mechanism formed in the part of concrete penetrated by the CPSM. We analyzed the chemical composites, in order to identify the mechanism of CPSM and to evaluate the penetrated depth. As shown in the results, SEM observes the acicular-structured crystals filling capillary pores for mortar substrate of the internal microstructure beneath the concrete surface; meanwhile, XRD and FT-IR showed the main hydration products of CPSM to be C-S-H gel and CaCO3. Besides, MIP also shows CPSM with the ability to clog capillary pores of mortar substrate; thus, it reduces porosity, and appears to benefit in sealing pores or cracks. The depth of CPSM penetration capability indicated by TGA shows 0–10 mm of sealer layer beneath the concrete surface.

Factors Affecting the Effectiveness of Inorganic Silicate Sealer Material through Multi-Quality Characteristics

This study investigates the effectiveness of concrete protection with two inorganic silicate sealer materials (ISSMs). The Taguchi method and grey relational analysis (GRA) have been used to identify the key factors influencing concrete protection provided by the surface treatment. Seven control factors with two levels were selected. By using the orthogonal array L12 (27), 12 experiments are chosen and four tests—the compressive strength test, resistivity test, absorption test and permeability test—were performed. Results have shown that the major factors affecting the protection effectiveness of ISSM are the water-binder ratio of mortar substrate, age of substrate for sealer application, addition of pozzolanic material and sealer type.

Properties of Cement-Based Materials Containing Melting Incinerator Bottom Ash

This paper presents an experimental investigation on the effect of incinerator bottom ash (IBA) fineness and the cooled process of molten IBA on fresh mortar properties and compressive strength of hardened mortars. IBA with two finenesses, an original IBA, and a pulverizing incinerator bottom ash (PIBA) powder, with maximum particle size of 4.75 and 0.074 mm respectively were used to partially replace sand and Portland cement at 0%, 10%, 20%, 30%, and 40% by weight. The pozzolanic activity characteristics of powder were obtained from melting the above PIBA in an electric-furnace at 1450 °C for 1 h. and chilled by quenching in water (WIBA) and air (AIBA). Results indicate that incinerator bottom ash caused a reduction in compressive strength, unit weight, and flowability values when used as a replacement for sand and cement. However, IBA can be processed by melting to regain reactive pozzolanic activity, which may be used to partially replace cement.

Waste-Based Pervious Concrete for Climate-Resilient Pavements

For the sake of environmental protection and circular economy, cement reduction and cement substitutes have become popular research topics, and the application of green materials has become an important issue in the development of building materials. This study developed green pervious concrete using water-quenched blast-furnace slag (BFS) and co-fired fly ash (CFFA) to replace cement. The objectives of this study were to gauge the feasibility of using a non-cement binder in pervious concrete and identify the optimal binder mix design in terms of compressive strength, permeability, and durability. For filled percentage of voids by cement paste (FPVs) of 70%, 80%, and 90%, which mixed with CFFA and BFS as the binder (40 + 60%, 50 + 50%, and 60 + 40%) to create pervious concrete with no cement. The results indicate that the complete (100%) replacement of cement with CFFA and BFS with no alkaline activator could induce hydration, setting, and hardening. After a curing period of 28 days, the compressive strength with different FPVs could reach approximately 90% that of the control cement specimens. The cementless pervious concrete specimens with BFS:CFFA = 7:3 and FPV = 90% presented better engineering properties and permeability.

An M-Taiwan experience on mobile WiMAX

The wireless technologies and applications are developed very quickly in recent year. With the rapid development and enhancement on wireless technology, the wireless keeps expanding and increasing its deployed has become more sophisticated and competitive. Taiwan grapples with the challenge from the new wireless technologies and is making their endeavor upon this issue. In this paper, we introduce about M-Taiwan project for mobile WiMAX and describle the mobile WiMAX trial in M-Yilan for its architecture. Moreover, we survey some measurement indexes and tools to measure its performance. For the measurement of effective range of mobile WiMAX coverage, we propose a new method that generates the interpolation surface for the measurements of received signal strength indicator RSSI and CINR. Interpolation predicts values for cells in a raster can be used to predict unknown values for any measured point of received signal strength.

Variation in Fineness of Cement-Based Composites Containing Sugarcane Bagasse Ashes

This study is aimed to evaluate the effect of sugarcane bagasse ash fineness on the properties of cement-based composites. Three sugarcane bagasse ash contents (10, 20 and 30% by weight of cement) and three particle sizes of bagasse ash (particles less than 45, 75 and 150 μm) were used as a partial replacement for cement in mortar specimens with a constant water/cementitious ratio of 0.55. The pozzolanic strength activity test, compressive strength test and scanning electron microscope observations were conducted and compared. Test results indicated that the compressive strength decreased with the addition of sugarcane bagasse ash content increased. Addition of sugarcane bagasse ash to replace cement in cementitious composites could provide hydration and pozzolanic reaction, but it would still keep more rugged and some larger pores observed from the paste surface and resulted in the weaker microstructures and poorer properties in cementitious composites. In conclusion, the critical usage of sugarcane bagasse ash is 10 % with 45μm particles.

The Component Analysis of Penetration Sealer Materials

Nowadays, its more common of dispensing a topping material like concrete crystalline penetration sealer materials (CSM) onto the surface of a plastic substance such as concrete to extend its service life span by surface protections from outside breakthrough. Its known as the CSM may penetrate into the existing pores or possible cracks in such a way that it may form crystals to block the potential paths which provide breakthrough for any unknown materials. Even though all kinds of test data and researches have been reported to boast of its advantages in both theoretical technologies and application functions, to accept that as an agreed fact, namely the major components and those proportions have not been fully announced in public or research. This study employed various experiments, such as scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), X-ray fluorescence (XRF) and Fourier transform infrared spectroscopy (FT-IR), to identify key components of CSM for developing another type of CSM so that its components could be open for the public. There are two types of commercial CSM adopted for the tests and then thru a series of discusses of test results the most possible components of CSM are proposed as a future reference of CSM related researches.

Properties of Controlled Low Strength Material with Circulating Fluidized Bed Combustion Ash and Recycled Aggregates

This study aims to investigate the effect of adding circulating fluidized bed combustion (CFBC) ash, desulfurization slag, air-cooled blast-furnace slag and coal bottom ash to the controlled low-strength material (CLSM). Test methods include slump flow test, ball drop test, water soluble chloride ion content measurement, compressive strength and length change measurement. The results show that (1) the use of CFBC hydration ash with desulfurization slag of slump flow is the best, and the use of CFBC hydration ash with coal bottom ash and slump flow is the worst; (2) CFBC hydration ash with desulfurization slag and chloride ion content is the highest; (3) 24 h ball drop test (diameter ≤ 76 mm), and test results are 70 mm to 76 mm; (4) CFBC hydration ash with desulfurization slag and compression strength is the highest, with the coal bottom ash being the lowest; increase of CFBC hydration ash can reduce compressive strength; and (5) the water-quenched blast furnace slag and CFBC hydration ash would expand, which results in length changes of CLSM specimens.