Fabrication Experimental Study On New Insulation Building Materials Made From Fly Ash And Styrofoam

Along with the improvement of living standard and the increasingly serious problems of energy, people's request for thermal insulation property of residential houses increases. As a result, the research and development of insulation material has become one of the hot topics in construction material field. At the same time, using waste to develop new function materials is the first priority among the hot topics.The fly ash and the waste extruded polystyrene foam (EPS) are two major killers of environment. One of the new ways to develop new materials is to use it reasonably, changing waste into valuable. This paper aims at developing a new type of energy-saving insulating wall material by applying the two kinds of waste to insulation mortar to make the most of their advantages respectively.The main use value of fly ash is its activity, especially when it is used as the raw material of cement concrete. The cement concrete is one of the most important building materials. With the addition of fly ash, the content of cement will decrease, that is to say, it can reduce the consumption of resource and energy, and reduce the environmental pollution resulted from cement production; Under natural conditions, waste extruded polystyrene foam will not degrade in one or two hundred years because of its light weight and small size, which has increasingly led to serious white pollution and has destroyed ecological environment. However, it has many characteristics, such as light weigh (0.01-0.05g/cm3),innocuity,low water absorption,acid-alkali resistance,weather resistance,heat insulation,sound insulation, which can be used to develop heat preservation and thermal insulation material to change waste into valuable. This paper uses lime-gypsum as the activator of fly ash, adding with modified extruded polystyrene foam, to develop lime-gypsum- fly ash-EPS insulation mortar with good performances for keeping temperature and durability. This kind of insulation mortar fully meets the demand for building heat preservation and thermal insulation mortar and insulation building blocks, it belongs to green energy-saving building material. The main synthetic raw material of NF-30 admixture that used in insulation mortar is the waste of coal coking--washing oil. Because the washing oil and the naphthalene are similar compounds, the synthetic water-reduce is not only of good properties but also the other waste that added in the insulation mortar block. We studied many aspects of insulation mortar; it included the composition of raw materials,experiment ideas,technical means,hydration,hardening. The detailed description is as follows:(1)Using many basic theories of various subjects synthetically, such as test means,organic chemistry,thermodynamics,phase analysis,physical properties of materials, we discussed the reaction mechanism of insulation masonry mortar consisting of fly ash and EPS and the possibility of developing insulation masonry mortar, according to the physical characteristics and the chemical composition of fly ash,the physicochemical properties and the activation mechanism of lime-gypsum,the physicochemical properties and the modification methods of waste EPS;(2)We studied the hydration and the harden mechanism of fly ash mortar activated by lime-gypsum systematically, and analyzed the physicochemical properties of the mortar by many basic physical and chemical properties test means in activation system. We used lime-gypsum to activate the potential activity of fly ash. We discovered that the optimal amount of fly ash is 20%-25%;(3)The XRD analysis,the TGA-DTA hydration products thermomechanical analysis,the observation of the products of hydration time under SEM show:The activity of fly ash is activated by lime effectively on condition of equal content of CaO. The gypsum reacts with fly ash and forms ettringite in the presence of Ca(OH)2, which is used as a sulphate activator for hydration of fly ash. The activating effect becomes stronger because of the generation of dihydrate gypsum with high dispersibility and high surface activity. The hydrations of fly ash and anhydrite promote each other; the effect of activation of lime-gypsum for fly ash is weak in early age. In later times, the hydration products, such as Ca(OH)2,C-S-H,AFm, develop very well. Lime- plasters plays an important role in the activation for the potential activity of fly ash; the appearances of hydration products in 28 days and 60 days later show: on the one hand, lime-plasters activates the activity of fly ash and compensates for the strength loss of cement mortar; on the other hand, it illustrates that the activity of fly ash is not activated completely, there are still some fly ashes with weak activity in later times. The interface of mortar, activated by lime-gypsum, tends to be orderly in the later hydration period. It has higher weatherability and relative lasting later strength. Moreover, it discovers the possibility of developing the mortar of lime-plasters-fly ash;(4)The synthesis of admixture NF-30 which is required by insulation mortar shows: The water-reducer will get the best comprehensive performances when we add oxidant MO,30% washing oil and control the conditions as follows:PH value is 7-9, sulfonation time is 2.5 hours, condensation time is 5 hours and sulfonation temperature is 160℃. The properties of cement concrete modified by NF-30 are very good:good dispersibility, fast hydration speed, more hydration products, and higher early strength. The homemade NF-30 additive cost little but it has the equal properties to pure naphthalene, which pioneers a new way to utilize waste coking washing oil;(5)The preparation of fly ash-EPS in a certain grain degree shows:Using grain degree of 0.16--2.0mm, adding 20% fly ash and 2.0%-2.5% EPS, the insulation mortar gets the best comprehensive performances;(6)TGA-DTA hydration products thermomechanical analysis and XRD analysis of the fly ash-EPS insulation mortar without lime-gypsum show: Compare to standard mortar sample, the fly ash-EPS insulation mortar without lime-plasters hydrates slowly and has low strength, but its physical properties are better than many insulation materials doped with others:good durability\weather resistance,good performance for keep temperature[0.455(W/m·K)].This reveals the possibility of developing insulation mortar blocks and the necessity of activating the fly ash by lime-plasters;(7) In the premise of activating the potential activity of fly ash by lime-desulfurization plasters, we take advantage of the capacity of heat preservation of EPS to develop a novel functional material. The best proportion is 20% fly ash and 2.5% EPS, and then we obtain the insulation mortar of good properties. Its coefficient of heat conductivity is 0.531W/(m·k), far below that of blank mortar(0.938W/(m·k)), it meets the Energy-saving standard that the coefficient of heat conductivity is not higher than 1.5W/(m·k) in Lianghuai valley. Moreover, it confirms that the activation of lime-gypsum results in the dense insulation mortar, its coefficient of heat conductivity is slightly bigger than that of insulation mortar without lime-gypsum activator, but it has the best comprehensive performances;(8)The fly ash-EPS insulation mortar block has good comprehensive performances under the action of activator.:lasting later strength,strong resistance to acid,excellent frost resistance,low moisture absorption low water absorbability,high coefficient of softening, water resistance and good performance in durability.117kg fly ash and 14.6kg EPS and desulfurization plasters 29.3 kg will consumed to produce Im3 insulation mortars, which utilizes many kinds of wastes simultaneously and changes waste into valuable because both of the two raw materials are environmental pollutants;(9)XRD analysis to the hydration products of the fly ash and styrofoam new insulation mortar shows:In early age, the hydration products are small in quantity, small in size, and they do not develop perfectly, the main hydration products are hydrated calcium aluminate (C4AH13),hydrated calcium silicate (C-S-H) and calcium hydroxide (CH); 28days later, the main hydration products are hydrated calcium silicate (C-S-H),hydrated calcium aluminate (C4AH13)., ettringite (AFt) and calcium hydroxide (CH). At the same time, the calcium aluminosilicate hydrate (C3ASH4) and the tobermorite (Ca(Si5O18H2)·4H2O) grow in number and the crystal grows perfectly.60 days later, there are hydrated calcium silicate (C-S-H),ettringite (AFt),calcium hydroxide (CH),calcium aluminosilicate hydrate (C3ASH4) and tobermorite (Ca(Si5O18H2)·4H2O) in large quantities. Moreover, with the prolongation of hydration, there are more hydration products, the crystal grains grow up, and the crystal form is stable. It explains in further steps:the activation effect of lime-gypsum on fly ash is not obvious in early age, but remarkably at a later stage. This confirms that the activity of fly ash activated by lime-gypsum can compensate the strength loss which is caused by adding waste fly ash and EPS, and then the use possibility of insulation mortar increases;(10)SEM scan analysis to fly ash and styrofoam new insulation mortar shows:At early age of hydration (3days), there are hydration products in large quantities: hydrated calcium aluminate> C-S-H gel,Ca(OH)2 and so on, but they are small in size and they do not develop perfectly, the main structure is sheet or fibrous, the void ratio is big.28 days later, there are more hydration products, they grow up continuately and develop perfectly, the void content decreases and the structure become dense. At later period of hydration (60 days later), the cement clinker and the fly ash have hydrated mostly, hydration reaction tends to come to an end, the amount of hydration products increases, the size and the morphology of the hydration products develop perfectly, the structure become dense, the void content decreases and the surfaces become flatter, which is consistent with the results of macroscopical physical experiments;(11)The fly ash and styrofoam new insulation mortar block is a new self-insulation environmental material. It can utilize the waste and save energy. Moreover, it can suit the climatic conditions in hot summer and cold winter region and can meet the demand for energy efficiency in buildings. According to the climate characteristics in Lianghuai valley, the possibility that the fly ash-EPS insulation mortar block appears condensation is low, it has large heat resistance, its heart bridge is less than that of general bearing concrete, there is less building energy loss and it belongs to engry-saving building products;(12) The processing technology of the fly ash and styrofoam new insulation mortar block is completed all at once, with high security, so it is easy to promote.The research work lays the foundations for further utilization of fly ash,desulfurization plasters and extruded polystyrene foam;it opens up the new way to develop new energy-efficient wall materials at the same time. Thereby, this material has good economic and social benefit;...