Abstract: Concrete curing is of paramount importance in order for concrete to meet performance requirements. Conventionally, curing has been conducted by means of water sparkling, wet burlap or a curing compound. For performance and environmental reasons, internal curing has been gaining increased attention. However, more data is needed for the effectiveness of this curing technique when used in various concrete mixtures. This investigation addresses potential utilization of internal curing in high performance concrete (HPC). Internal curing was introduced by means of three aggregates: perlite, pumice and recycled aggregates; all of which were incorporated into HPC mixtures. Conventional mixtures were prepared and were thoroughly cured either by water or by a curing compound or left non-cured. Fresh concrete and Hardened concrete properties were assessed including slump, unit weight, compressive and flexural strength, and durability tests as shrinkage assessment, rapid chloride permeability test (RCPT) and abrasion resistance. Experimental work is backed up with a simplified feasibility analysis with case study, incorporating initial and future costs to better judge potential of this technique. The outcome of this study uncovers that the addition of pre-wetted lightweight aggregates can prompt an enhancement in concrete workability and durability accompanied by a reduced shrinkage. Compressive and flexural strengths decreased with the increased replacement dosages, however several dosages were tested to reach a figure of optimum replacement. Results of this study reveal the potential of this technology in saving fresh water as well as the costs saved in maintenance and rehabilitation works.

Internally cured concrete has been rapidly emerging over the last decade as an effective way to improve the performance of concrete. Internal curing (IC) holds promise for producing concrete with an increased resistance to early-age cracking and enhanced durability. It is a simple and effective way to cure concrete.

Environmental exposure is one of the primary causes of concrete pavement deterioration, specifically cyclic freezing and thawing, as is common in Kansas. Rehabilitation of deteriorated concrete pavement is a common pavement life-extension strategy, and a variety of rehabilitation techniques are often utilized depending on the level of pavement distress. Budgetary constraints, however, often dictate use of partial and full-depth patching methods to rehabilitate deteriorated concrete pavement rather than replace an entire road. For roadways with high traffic volume, patching is often done overnight within few hours. These repairs include removing the old concrete and preparing the location for new concrete, which must achieve at least 1,800 psi compressive strength 6 hours prior to opening to traffic to avoid compromising future durability. Current patches last less than 10 years despite a nominal 20-year service life. This study utilized an internal curing technique to produce durable high early strength concrete for patching. Because desorbing water throughout the concrete matrix improves the microstructure and reduces porosity, lightweight aggregates and crushed concrete aggregates were each used to desorb water and provide internal curing. Tests were conducted to evaluate compressive strength, autogenous shrinkage, length change, and freezing and thawing related to mass change, length change, and relative dynamic modulus of elasticity (RDME). In contrast to ASTM C157, which only measures drying shrinkage after 14 days of curing, autogenous shrinkage of concrete was measured in this study. KTMR-22, developed by the Kansas Department of Transportation, was used to evaluate freeze-thaw durability of internally cured repair mixtures because this method subjects test specimens to a much harsher test regimen than ASTM C666. For example, KTMR-22 utilizes 660 cycles that simulate 20 years of exposure to 33 cycles of freezing and thawing compared to ASTM-666 exposure of only 300 cycles. Results showed that the mixture made with lightweight aggregate and low cement content met all requirements for expansion and RDME. This mixture also had minimum autogenous shrinkage among all the mixtures.

Advances in Construction and Demolition Waste Recycling: Management, Processing and Environmental Assessment is divided over three parts. Part One focuses on the management of construction and demolition waste, including estimation of quantities and the use of BIM and GIS tools. Part Two reviews the processing of recycled aggregates, along with the performance of concrete mixtures using different types of recycled aggregates. Part Three looks at the environmental assessment of non-hazardous waste. This book will be a standard reference for civil engineers, structural engineers, architects and academic researchers working in the field of construction and demolition waste. Summarizes key recent research in recycling and reusing concrete and demolition waste to reduce environmental impacts Considers techniques for managing construction and demolition waste, including waste management plans, ways of estimating levels of waste, and the types and optimal location of waste recycling plants Reviews key steps in handling construction and demolition waste

Author Biography: Dr. Mohammad Abdul Mannan was born at a simple family of a small village, Aktarpur, Rangiarpota, Jibonnagar, Chuadanga, Bangladesh. He has obtained B.Sc. (Civil Engineering) degree with first class, MSc in Civil Engineering and PhD in Concrete technology. He has started carrier as lecturer at BIT Rajshahi (now RUET), Bangladesh followed by AJP consulting firm, then Universiti Malaysia Sabah (UMS) and is now a Professor of Department of Civil Engineering, Universiti Malaysia Sarawak, Malaysia. He is the inventor of few construction products. Based on 30 years of experience in teaching, professional practice and research, his vision is to be excellence in research on Innovative Construction Material and Structure. Book Description: Due to a high demand in construction and furniture industries worldwide, natural resources such as stones and wood as non-renewable resources are being depleted. Thus, researchers are focusing on renewable resources as alternative materials. As such, the utilisation of abundant solid wastes and byproducts, which are discharged from agriculture, industry and municipalities present an alternative to the conventional materials for the construction and furniture industries. These solid wastes and byproducts, when properly processed have shown to be effective and can readily meet design specifications. Agricultural solid wastes from oil palm distributors such as Oil Palm Shell (OPS) and Empty Fruit Bunch (EFB), which are abundant in agro-based countries, present an interesting alternative to the conventional aggregate in lightweight concrete and artificial plank production, respectively. At present, palm oil producing countries are Barkina Faso, Benin, Burundi, Cameroon, Central African Republic, Colombia, Costa Rica, C�te d'Ivoire, Democratic Republic of Congo, Ecuador, Equatorial Guinea, Gabon, Gambia, Ghana, Guinea Bissau, Guinea, Honduras, India, Indonesia, Liberia, Malaysia, Mexico, Nigeria, Papua New Guinea, Peru, Republic of Congo, Senegal, Sierra Leone, Tanzania, Thailand, Togo, Uganda, Venezuela and others. In Malaysia, oil palm plantations cover over 5 million hectares, and annual production of OPS as solid waste from 450 oil palm mills is more than 6 million tons. This large amount of OPS as a renewable green aggregate can contribute to overcoming the over dependence on depletable resources for concrete production. The civil engineering projects are of a larger scale; they need sustainable materials in order to gain a greater momentum of growth. The major technical characteristics of OPS solid waste must be primarily understood before each particular use. Therefore, there is a need to highlight the importance of OPS to be used in the construction industry.

This is the state-of-the-art report prepared by the RILEM TC “Application of Super Absorbent Polymers (SAP) in concrete construction”. It gives a comprehensive overview of the properties of SAP, specific water absorption and desorption behaviour of SAP in fresh and hardening concrete, effects of the SAP addition on rheological properties of fresh concrete, changes of cement paste microstructure and mechanical properties of concrete. Furthermore, the key advantages of using SAP are described in detail: the ability of this material to act as an internal curing agent to mitigate autogenous shrinkage of high-performance concrete, the possibility to use SAP as an alternative to air-entrainment agents in order to increase the frost resistance of concrete, and finally, the benefit of steering the rheology of fresh cement-based materials. The final chapter describes the first existing and numerous prospective applications for this new concrete additive.