Preparation And Performance Research Of The Luminescent Concrete

Abstract:Light concrete is a day to absorb sunlight or ultraviolet light, and the light energy is stored, the stored energy in the evening in the form of visible light released from the light concrete. It can be used in the square, park, walking street, entertainment, leisure venues, the laying of various patterns, beautify, lighting effects. Light concrete preparation, lies in the preparation of long Yu Hui materials fluorescent powder.The key of preparating Luminescent concrete is the preparation of long afterglow materials which are also phosphors. Long afterglow materials themself can not be directly as end products,they must be combined with other materials to be applied. Concrete is the most commonly used material in construction industry, it has more widely used in the construction of public facilities.It is the core of the building materials as loadbearing elements,the development and innovative research of concrete is very important.The CaO:xDy3+, yNa+phosphors,were synthesized by hish solid—State method, and the starting materials are CaCO3、Na2CO3and Dy2O3. The effects of the Dy3+,Na+doping concentration on luminescent properties were studied by TG/DSC,XRD and photoluminescence(PL)spectra.The results indicated that when the sinter temperature preponderates over950℃,the main phaseof the phosphor is CaO;To improve the calcination temperaturethe and lengthening of calcination time,did not affect the crystal structure of CaO matrix, only enhanced the diffraction peaks. And, with the increase of calcining time, the luminous intensity of the phosphor is also increased, but after2.5h,the increase of emission intensity was not obvious, therefore,get the calcination temperature is1050℃,the calcination time is2.5h;When x=0.02,y=0.15we obtained the best luminescent properties of CaO:xDy3+, yNa+phosphors;Na+ion effectively enhances the luminescent properties of phosphors;The maximum emission wavelength is about480nm (blue),corresponding to4F9/2�'6H15/2of Dy3+; There are a series of spectral lines in the240-420nm range of excitation spectrum,and the strong excitation peak located at360and375nm.The obtained phosphor is incorporated into the raw materials of concrete, Which was prepared to luminescent concrete. The effects of phosphor the doping concentration on the cement hydration and mechanical properties of concrete were studied, and studying the SEM analysis of phosphor and the obtained luminescent concrete as well as on the light-emitting time of the luminescent concrete. The results indicated that phosphor is incorporated into the concrete, then will affect the cement hydration process, thus affecting the final strength of concrete; The luminous time of the concrete will growth with the phosphor content increased,ang the afterglow attenuation is slow, and the concrete luminous time is shortened with the increase of coating thickness; With the increase of the phosphor content, compressive and flexural strength of the concrete is reduced, but phosphor does not chemically react with other materials in the concrete, and still has its unique luminescent properties.