Hamidah Mohd Saman

Evaluation of Medium-Rise Reinforced Concrete Building Performance under Low Intensity Earthquake Effect

The paper presents an evaluation of medium-rise reinforced concrete building in Johor which is subjected to low intensity earthquake effects. Even-though Malaysia is outside the earthquake region, the country had experienced and did suffer from major cases due earthquake in the past like tsunami. Engineers should concern and consider the loading for reinforced concrete building due to earthquake in the building design procedure. The study addresses the performance of critical frame reinforced concrete building when subjected to earthquake motion. The building of Marlborough College Malaysia chooses as model. The building was analyzed using Finite Element Modelling (FEM) using IDARC (2D) with respect to various earthquake intensities obtained from Time History Analysis (THA) data. The yield point at the beam-column connections was analyzed to determine the damage index and damage level of the building subjected to the various earthquake intensities. The building performed the early yielding point at 4.2650 sec for beam element at the intensity of 0.15g. Based on the results, it was found that the critical frame of Condominium Marlborough College Malaysia can stand an earthquake occurrence with intensity up to 0.20g. There is no structural damage some non-structural damage is expected in the non-linear analysis of modal frames. The building was also categorized as the one in the light damage level.

Palm Oil Fuel Ash and Ceramic Sludge as Partial Cement Replacement Materials in Cement Paste

Palm oil fuel ash (POFA) and ceramic sludge (CS) are waste materials that found produced abundantly in the palm oil and the porcelain industrial sectors respectively. However, these waste materials are improperly managed that proved can give adverse impacts to the environment and human’s health. This research was carried out in order to identify the potential of POFA and CS as partial cement replacement materials in cement paste. POFA was prepared at 10, 20, 30 and 40 % replacement of Ordinary Portland cement (OPC) and CS was prepared at 60 % substitution of the cement paste. The effects of POFA and CS in the cement paste in term of compressive strength at 1, 3, 7, and 28 days of curing were also determined. The results indicated that the optimum compressive strength of cement paste was achieved by P2 containing 10 % POFA: 30 % OPC: 60 % CS. As a result, the utilisation of POFA and CS as partial cement replacement materials can significantly reduce the high amount of OPC usage apart of reducing the environmental problems and human’s health problems.

Active Fatigue Crack Detection and Classification of Reinforced Concrete Beams Using Acoustic Emission

Active crack due to fatigue loading in reinforced concrete beams is a crucial phenomenon and need to be classified. Twelve beams were tested under three point loading with various fatigue loading in conjunction with acoustic emission monitoring. A total of six phases of fatigue maximum loading were performed on the reinforced concrete beams with frequency of 1 Hz, sinusoidal wave and 5,000 cycles for each phase. Two indices of qualitative analysis of acoustic emission signal such as RA value and average frequency were determined to classify the crack of the reinforced concrete beams subjected to the fatigue loading. The relationship of these two indices showed promising results corresponding to the development of active crack in the reinforced concrete beams as the maximum fatigue load increased.

Factors influencing Malaysian construction firms in venturing into international market

A tremendous demand of development worldwide has gained interest of Malaysian construction firms to venture into international construction domain. Identifying and analyzing major determinants of the firms internal and external factors are crucial in order to ease the complexity in global market expansion. This paper identifies the relative importance of the strengths, weaknesses, opportunities and threats (SWOTs) related to the internationalization of Malaysian contractors. Responses were received from thirty one (31) Class A and Grade 7 Malaysian construction firms registered with CIDB Malaysia in 2010. The findings reveal that “good track record”, “specialist expertise” and “international network” were the most influential strength factors for the firms to effectively compete in international market. However, “shortage of financial resources” as well as “material and labor resources” contributed to the weaknesses in exploring international market. The study also reveals that “opening up new market”, “technological advancement” and “beneficiary international agreements” offered huge opportunities in overseas market. Nevertheless, factors such as “bribery in the host country”, “increase of interest rate” and “lack of awareness” were perceived as the threats due to difficulties in dealing with moral problems, financial risks and unfamiliar environment within the host country. Finally, this study is of relevance to Malaysian construction firms as it systematically highlights the internal and external factors those may affect their performance in international market. These findings may assist them to make necessary preparatory works by enhancing the strengths, reducing the weaknesses, seizing the opportunities and facing the threats in international market, as these elements are consistently changing.

Strength Development of Pervious Concrete Embedded with Latex and Polypropylene Fiber

Nowadays, in Malaysia, there is flooding issue during heavy rainfall. This is caused by an increase in infrastructure and construction. So, the surface of the water that infiltrates into the earth is very limited. However, to overcome this situation, pervious concrete is the best alternative solution. Pervious concrete has been increasingly used to reduce the amount of runoff water to the drainage system and sidewalks. However, the mechanical properties of pervious concrete are lower in compressive strength and has limited usage of application. These investigations will be carried out to determine the strength of pervious concrete with different percentages of polypropylene fibers. In this study, a series of volume polypropylene fiber and SBX latex, which is fixed to 0, 0.5, and 1.0% will be used in pervious concrete. The result will indicate the effect of polypropylene fibers and inclusion of SBR latex as admixture and modify concrete properties for the strength development of pervious concrete. Polypropylene fiber existence incorporates with SBR latex effect in the permeability of pervious concrete. SBR latex also helping in strengthen the bonding of pervious specimens since it is high in tension.

Waste Paper Sludge Ash (WPSA) as Binder in Solidifying Water Treatment Plant Sludge (WTPS)

Water treatment plant sludge (WTPS) is pathogen and heavy metals that can harm human health and the environment. As strict regulation had been implemented, WTPS is advised and must be treated before the waste is transported to landfill. Therefore, this research is conducted to solidify WTPS with an alternative waste material. The waste material so called as waste paper sludge ash (WPSA) was chosen as binder to be used to solidify WTPS. WPSA is a waste that is produced in bulk at the recycled paper factories. Somehow, its potentiality, especially as cement replacement materials is unknown. The objective of this research is to investigate the possibility of using WPSA as an alternative replacement material of cement in solidifying the WTPS. WPSA was used in proportions of 10, 20, 30, and 40 % as cement replacement by volume along with WTPS in fixed quantity. An additional mix without WPSA solidifying WTPS is also prepared. The effectiveness of WPSA in solidifying WTPS was determined based on the compressive strength achieved on 1, 3, 7, and 28 days of curing. High replacement amount of WPSA with at least 0.34 N/mm2 compressive strength will be selected as the best mix. Based on results obtained, the compressive strength of solidified WTPS increased with increasing curing days for all mix types. The smallest particle size and highest surface area of WPSA had contributed to the condition. Although, the compressive strength of solidified WTPS decreases with increasing WPSA percentage replacement. In addition, WPSA used in this research was a non-pozzolanic material with very porous surface area and irregular shape. In conclusion, a mix of 40 % WPSA labeled as W5 is a more sustainable mix binder in solidifying WTPS. Although, W2 with 10 % of WPSA substitution had passed the landfill acceptable limit at 0.34 N/mm2.

Enhancement of Thermophilic (Geobacillus stearothermophilus) Cement–Sand Mortar Properties

This study describes the incorporation method of Geobacillus stearothermophilus (ATCC 12978) inside the cement–sand mortar. Different cell concentrations of Geobacillus stearothermophilus were incorporated and the improvement in the properties of cement–sand mortar has been observed. Based on the study conducted, the involvement of Geobacillus stearothermophilus (ATCC 12978) has a positive impact to improve the performance of cement–sand mortar in terms of compressive strength and water absorption characteristic as compared to the controlled mortar. The incorporation of Geobacillus stearothermophilus has catalyst the occurrence of wollastonite (CaSiO3) that has proven capable to the enhanced concrete properties by modifying concrete pore structures. This study shows that the optimum concentration gives the most enhanced properties of the resulted cement–sand mortar as 1 × 109 cfu/ml. The current work demonstrates that the direct involvement of Geobacillus stearothermophilus in mortar has a great potential to enhance concrete performance in such natural way.

TFGM a New Composite Material with Palm Oil Fuel Ash

Textile fine grained mortar (TFGM) is a composite construction material which provides another alternative to strengthen and repair existing concrete structures. TFGM is a combination of fine grained mortar (FGM) made of waste material with textile fabrics. The strengthening approach significantly increases both the ultimate load carrying capacity and the serviceability. FGM is a special binder matrix with maximum grain size of 600–1 mm. Therefore, less than 2 mm mortar thickness is needed between the textile layers due to the small aggregate size. In addition, 10 % of cement content in FGM is replaced by palm oil fuel ash (POFA) as a waste material. The utilization POFA can reduce the carbon dioxide emission generated by cement, which can be harmful to the environment In this study, plain concrete prism with size of 100 mm × 100 mm × 500 mm was produced. Specimens were strengthened by using alkali resistant (AR) glass fabrics impregnated with FGM. Four levels of strengthening consisting of 2, 4, 6 and 8 layers fabric were used on three replicate specimens in each category. Strengthened concrete prisms were subjected to monotonic load with three-point bending test to determine the effect of the strengthening process and the number of fabric layers on the behaviour of concrete prism. The recorded measurements on the test specimens were evaluated for the ultimate flexural strength and deflection. TFGM significantly contributed on the flexural load carrying capacity and ductility of concrete prisms. The contribution of these composites varies according to the number of fabric layers. The flexural capacity increased about threefold from unstrengthened plain concrete prism.

Linking Entry Timing (ET) and Entry Mode (EM) Decisions in International Market Expansion by Malaysian Construction Firm: Toward the Development of ETEM Model

Neglecting to properly choose the right combination of entry mode and entry timing strategies can lead to poor performance in international business ventures. The paper focuses on the linking of entry timing (ET) and entry mode (EM) decisions and the factors influencing both decisions. By consolidating the findings for both entry decisions, an ETEM model to guide the construction firms to access the targeted markets will be developed. The questionnaire surveys were sent to 115 Malaysian construction firms listed under Construction Industry Development Board (CIDB) Malaysia with 39.1 % response rate. The logistic regression (LR) model revealed that the majority of construction firms have chosen to be the late movers (LMs). Factor analysis carried out shows that the factors significantly influenced the firms’ entry timing decision as LMs are the firm’s international experience, level of knowledge, research and development intensity, competencies in project management, specialist expertise and technology, and financing capacity. The multinomial logistic regression (MLR) model has shown that majority of the construction firms preferred both equity (EQ) and non-equity (NEQ) entry modes. The factor analysis revealed that the factors that significantly influenced the firms’ entry mode decisions to choose both types of entry mode are the firm’s management of quality and risk attitudes, strong resources, experience in similar works, ability to assess market signals and opportunities, superior management and organizational dynamic capabilities, availability of partner/alliance, and existence of strict time limitations. The consolidation of findings shows that the majority of the Malaysian construction firms were the late movers, and they preferred both EQ and NEQ entry modes. Hence, this study contributes to an improved understanding of particular relationships that exist between the entry timing and entry mode decisions made by firms into international market.

Development of entry location, entry timing and entry mode decision model for construction firms in international markets

The international market expansion process involves a combination of many strategic entry decisions. Most previous studies have dealt with entry location, entry timing and entry mode (ELETEM) decisions in an isolated way by considering one dimension or a combination of dimensions in particular. Although there have been various models relating to international market entry decisions, there is currently no model that attempts to integrate the factors linking the ELETEM decisions for construction firms. The purpose is to determine a linkage between the ELETEM decisions by incorporating the factors that are mutually inclusive and have significant influence on these decisions. Forty-five (45) Malaysian contractors undertaking projects in international markets responded to the survey. The findings suggested that the mutually inclusive and significant factors (MISFs) influencing the ELETEM decisions were: the firm’s ability to assess market signals and opportunities, the firm’s resources and the firm’s experience in similar works. It was observed that the firms had adopted long-term strategies, repositioned their knowledge from research and development activities and readapted their resources and experience in their global operations. The findings led to the development of the ELETEM decision model to guide interested firms in making better decisions for their future international ventures.